SHE GOT UP LATE AND RUSHED TO THE BUS STOP.A. WENT LEISURELY B. WENT Q...

Câu 30: She got up late and rushed to the bus stop.A. went leisurely B. went quickly C. dropped by D. came intoRead the following passage and blacken the letter A, B, C, or D on your answer sheet toindicate the correct answer to the following questions.Birds that feed in flocks commonly retire together into roosts. The reasons for roostingcommunally are not always obvious. but there are some likely benefits. In winter especially. it isimportant for birds to keep warm at night and conserve precious food reserves. One way to dothis is to find a sheltered roost. Solitary roosters shelter indense vegetation or enter a cavity -horned larks dig holes in the ground and ptarmigan burrow into snow banks - but the effect ofsheltering is magnified by several birds huddling together in the roosts, as wrens, swifts. browncreepers, bluebirds. and anis do. Body contact reduces the surface area exposed to the cold air, sothe birds keep each other warm. Two kinglets huddling together were found to reduce their heatlosses 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 theyreturn in the evening some will have fed well, but others may have found little to eat. Someinvestigators have observed that when the birds set out again next morning, those birds that didnot feed well on the previous day appear to follow those that did. The behavior of common andlesser kestrels may illustrate different feeding behaviors of similar birds with different roostinghabits. 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 kestrelroosts and hunts alone, but the lesser kestrel roosts and hunts in flocks, possibly so one bird canlearn from others where to find insect swarms.Finally. there is safety in numbers at communal roosts since there will always be a fewbirds awake at any given moment to give the alarm. But this increased protection is partiallycounteracted by the fact that mass roosts attract predators and are especially vulnerable if theyare on the ground. Even those in trees can be attacked by birds of prey. The birds on the edge areat greatest risk since predators find it easier to catch small birds perching at the margins of theroost.