Many kinds of wild animals are . We must do something to save them.A. in factB. on holiday

问题补充：

Many kinds of wild animals are . We must do something to save them.

A. in fact

B. on holiday

C. on time

D. in danger

答案：

A. in fact

B. on holiday

C. on time

(答案→)D. in danger

解析：根据后文的内容可知，be in danger，故选D