It has been evident that too many children in the city are left when their development re

问题补充：

It has been evident that too many children in the city are left when their development requires parents’ close attention.

A. alone

B. off

C. out

D. behind

答案：

(答案→)A. alone

B. off

C. out

D. behind

解析：

这题考查词组辨析：Leave alone 听其自然，不管，leave off停止，leave out遗漏，leave behind留下，句意是：很显然，城市里的很多孩子在发展需要父母密切关注时，却被置之不理。选A。