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.
-
Aacting as sentinels and to sound
分析该选项
-
Bacting as sentinels and sounding
分析该选项
-
Cto act as sentinels and sound
分析该选项
-
Dto act as sentinels and to sound
分析该选项
-
Eto act as a sentinel sounding
分析该选项
显示答案
正确答案: B