Birds that feed in flocks commonly

Birds that feed in flocks commonly retire together into roosts. The reasons for
roosting communally are not always obvious, but there are some likely benefits.
In winter, especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in (5) dense vegetation or enter a cavity - horned larks dig holes in the ground and ptarmigan burrow into snow banks - but the effect of sheltering is magnified by several birds huddling together in the roosts, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to (10) reduce their heat losses by a quarter and three together saved a third of their heat. The second possible benefit of communal roosts is that they act as “information centers.” During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out (15) again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roosts and (20) hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially (25) vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost.
9. What does the passage mainly discuss?
(A) How birds find and store food
(B) How birds maintain body heat in the winter
(C) Why birds need to establish territory
(D) Why some species of birds nest together
10. The word “conserve ”in line 3 is closest in meaning to
(A) retain
(B) watch
(C) locate
(D) share
11. Ptarmigan keep warm in the winter by
(A) huddling together on the ground with other birds
(B) building nests in trees
(C) burrowing into dense patches of vegetation
(D) digging tunnels into the snow
12. The word “magnified”in line 6 is closest in meaning to
(A) caused
(B) modified
(C) intensified
(D) combined
13. The author mentions kinglets in line 9 as an example of birds that
(A) protect themselves by nesting in holes
(B) nest with other species of birds
(C) nest together for warmth
(D) usually feed and nest in pairs
14. The word “forage”in line 12 is closest in meaning to
(A) fly
(B) assemble
(C) feed
(D) rest
15. Which of the following statements about lesser and common kestrels is true?
(A) The lesser kestrel and the common kestrel have similar diets.
(B) The lesser kestrel feeds sociably but the common kestrel does not.
(C) The common kestrel nests in larger flocks than does the lesser kestrel.
(D) The common kestrel nests in trees; the lesser kestrel nests on the ground.
16. The word “counteracted”in line 24 is closest in meaning to
(A) suggested
(B) negated
(C) measured
(D) shielded
17. Which of the following is NOT mentioned in the passage as an advantage derived
by birds that huddle together while sleeping?
(A) Some members of the flock warn others of impending dangers.
(B) Staying together provides a greater amount of heat for the whole flock
(C) Some birds in the flock function as information centers for others who are
looking for food.
(D) Several members of the flock care for the young.
18. Which of the following is a disadvantage of communal roosts that is mentioned in
the passage?
(A) Diseases easily spread among the birds.
(B) Groups are more attractive to predators than individual birds.
(C) Food supplies are quickly depleted.
(D) Some birds in the group will attack the others.
19. The word “they”in line 25 refers to
(A) a few birds (B) mass roosts
(C) predators (D) trees

Kết quả (Việt) 1:

Chim mà ăn trong đàn gia cầm thường nghỉ hưu với nhau vào roosts. Những lý do chođịa communally không phải luôn luôn rõ ràng, nhưng có một số lợi ích có khả năng.In winter, especially, it is important for birds to keep warm at night and conserve precious food reserves. One way to do this is to find a sheltered roost. Solitary roosters shelter in (5) dense vegetation or enter a cavity - horned larks dig holes in the ground and ptarmigan burrow into snow banks - but the effect of sheltering is magnified by several birds huddling together in the roosts, as wrens, swifts, brown creepers, bluebirds, and anis do. Body contact reduces the surface area exposed to the cold air, so the birds keep each other warm. Two kinglets huddling together were found to (10) reduce their heat losses by a quarter and three together saved a third of their heat. The second possible benefit of communal roosts is that they act as “information centers.” During the day, parties of birds will have spread out to forage over a very large area. When they return in the evening some will have fed well, but others may have found little to eat. Some investigators have observed that when the birds set out (15) again next morning, those birds that did not feed well on the previous day appear to follow those that did. The behavior of common and lesser kestrels may illustrate different feeding behaviors of similar birds with different roosting habits. The common kestrel hunts vertebrate animals in a small, familiar hunting ground, whereas the very similar lesser kestrel feeds on insects over a large area. The common kestrel roosts and (20) hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird can learn from others where to find insect swarms. Finally, there is safety in numbers at communal roosts since there will always be a few birds awake at any given moment to give the alarm. But this increased protection is partially counteracted by the fact that mass roosts attract predators and are especially (25) vulnerable if they are on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge are at greatest risk since predators find it easier to catch small birds perching at the margins of the roost.9. những gì hiện các đoạn văn chủ yếu là thảo luận?(A) làm thế nào chim tìm và lưu trữ thực phẩm(B) làm thế nào chim duy trì nhiệt độ cơ thể trong mùa đông(C) lý do tại sao chim cần thiết lập lãnh thổ(D) lý do tại sao một số loài chim làm tổ cùng nhau10. từ "tiết kiệm"trong dòng 3 là gần nhất trong ý nghĩa để(A) giữ lại(B) xem(C) xác định vị trí(D) chia sẻ11. ptarmigan giữ ấm trong mùa đông bởi(A) huddling với nhau trên mặt đất với các loài chim khác(B) xây dựng tổ trong cây(C) rắn vào bản vá lỗi dày đặc của thảm thực vật(D) đào đường hầm vào tuyết12. từ "phóng đại" trong dòng 6 là gần nhất trong ý nghĩa để(A) gây ra(B) lần(C) tăng cường(D) kết hợp13. tác giả đề cập đến tước mào vàng trong dòng 9 như là một ví dụ của các loài chim mà(A) bảo vệ mình bằng cách làm tổ trong các lỗ(B) làm tổ với các loài chim(C) làm tổ cùng nhau cho ấm áp(D) thường nguồn cấp dữ liệu và làm tổ trong cặp14. từ "thức ăn gia súc" trong dòng 12 là gần nhất trong ý nghĩa để(A) bay(B) lắp ráp(C) nguồn cấp dữ liệu(D) còn lại15. mà trong số các câu sau đây về ít hơn và phổ biến kestrels là sự thật?(A) kestrel thấp hơn và cắt phổ biến có tương tự như chế độ ăn uống.(B) cắt nhỏ nguồn cấp dữ liệu sociably nhưng kestrel thường thì không.(C) các tổ kestrel phổ biến trong đàn gia cầm lớn hơn không cắt thấp hơn.(D) các tổ kestrel phổ biến trong cây; Các tiểu cắt tổ trên mặt đất.16. từ "counteracted" trong dòng 24 là gần nhất trong ý nghĩa để(A) đề nghị(B) làm hạn chế(C) đo(D) hệ thống bơm xăng17. Which of the following is NOT mentioned in the passage as an advantage derivedby birds that huddle together while sleeping?(A) Some members of the flock warn others of impending dangers.(B) Staying together provides a greater amount of heat for the whole flock(C) Some birds in the flock function as information centers for others who arelooking for food.(D) Several members of the flock care for the young.18. Which of the following is a disadvantage of communal roosts that is mentioned inthe passage?(A) Diseases easily spread among the birds.(B) Groups are more attractive to predators than individual birds.(C) Food supplies are quickly depleted.(D) Some birds in the group will attack the others.19. The word “they”in line 25 refers to(A) a few birds (B) mass roosts(C) predators (D) trees