《2013
北京》21. volunteering gives you a chance lives, including your own. a. change b. changing c. changed d. to change 《答案》d 《解析》考查非谓语动词。意为：志愿者工作让你有一个可以改变生活的机会，包括你自己的生活。动词不定式作chance后置定语。《2013北京》22. don’t turn off the computer before closing all programs you could have problems a. or b. and c. but d. so 《答案》a 《解析》考查并列连词。此处考查句型：祈使句+ and/ or+ 句子。or表“否则”。
