Some bat caves, like honeybee hives, have residents that take on different duties such as defending the entrance, acting as sentinels and to sound a warning at the approach of danger, and scouting outside the cave for new food and roosting sites.
2.Some bad caves, like honeybee hives, have residents that take on different duties such as defending the entrance, acting as sentinels and to sound a warning at the approach of danger, and scouting outside the cave for new food and roosting sites. A. acting as sentinels and to sound B. acting as sentinels and sounding C. to act as sentinels and sound D. to act as sentinels and to sound E. to act as a sentinel sounding key :B 可是这个AND 怎么可以用几次啊,有点混乱。 20. Declining values for farm equipment and land, the collateral against which farmers borrow to get through the harvest season, is going to force many lenders to tighten or deny credit this spring. A. the collateral against which famers borrow to get through the harvest season, is B. which farmers use as collateral to borrow against to get through the harvest season, is C. the collateral which is borrowed against by farmers to get through the harvest season, is D. which farmers use as collateral to borrow against to get through the harvest season, are E. the collateral against which farmers borrow to get through to harvest season, are key: E 可是这个动名词做主语,不是谓语单数吗?还是Decling 是一个形容词,来个修饰values? 24. In recent years cattle breeders have increasingly used crossbreeding, in part that their steers shoudl acquire certain characteristics and partly because crossbreeding is said to provide hybrid vigor. A. in part that their sheers should acquire certain chracteristics B. in part for the acquisition of certain charcteristics in their steers C. partly because of their steers acqiring certain characteristics D. partly because certain characteristics should be acquired by their steers E. partly to acquire certain characteristics in their steers KEY:E 不太明白 part 的用法 啊,求高人指教。 诚心请教,我自己手打的。用误请见谅