Many children are in the countryside when their parents flood into the cities for jobsA.

问题补充：

Many children are in the countryside when their parents flood into the cities for jobs．

A. left behind

B. left off

C. left aside

D. left out

答案：

(答案→)A. left behind

B. left off

C. left aside

D. left out

解析：考查短语辨析。句意“当父母涌进大城市打工时，许多孩子都被留在乡下的家里了。”A“遗留，留下”；B“终端，戒除”；C“搁置”；D“漏掉，省略”。故选A。