Question

【题目】Birds' singing is sometimes a warning to other birds ______ away.
A.to stay
B.staying
C.stayed
D.stayed

Answer 1

【答案】A
【解析】句意：鸟叫有时是为了警告其他的鸟远离他们。空格置于句中，主谓与to do之间无逗号间隔，译为“为了”选A。