1．__________ you turn off all the lights when you leave the classroom.
A．Making sure B．To make sure
C．Being sure D．Make sure
解析：选D。考查非谓语动词。句意：当你离开教室时务必要关掉所有的灯。主句是一个祈使句，故D项正确。
2．(The climate conference was attended by 11,000 people，__________ it the largest UN gathering ever held.
A．making B．to make
C．made D．to be making
解析：选A。考查非谓语动词。现在分词表示事情发展的自然结果，而不定式表示出乎意料的结果。根据句意可知，应选A项。
