Upon ______the classroom， I started thinking about my mo Wap版

试题详情及答案解析

Upon ______the classroom， I started thinking about my mother.

A．leave	B．leaving
C．left	D．to leave

答案：B

试题分析：考察动名词用法。在非谓语动词中，介词的后面常接动名词做介词的宾语，形成介宾短语。句意：一离开教室，我就开始想妈妈。故B正确。
考点：考察动名词