12.It was in this very lab was in the charge of Professor Smith they did the experiment.A.where;that B.which;that C.which;where D.that;where
答案：B.本题考查定语从句与强调句的混用.分析题干,可将原句分解为：
1、It was in this very lab that they did the experiment.（此句为强调句,强调地点状语in this very lab；因为强调句中,去掉it was/is...that...这一结构,句子在结构与意义上完整,即为判断强调句的标准）
2、It was in this very lab (which was in the charge of Professor Smith) that did the experiment.（注：括号内的句子为定语从句,其先行词为this very lab,在此次指代“事物”,且做主语,则关系代词可以用that或which）
此类题目为高考所考查的重点内容,应该予以掌握.又如：
--- Where did you find your lost pen?
--- It was in the park ____ we visited that day ____ I found it.
A.what; that B.which; that C.where; that D.when; that
答案：B.设空第一处考查定语从句,先行词为the park,作定语从句中visited的宾语,则关系代词用that或which或省略；设空第二处考查强调句.
【将上面的题目稍加变动】
--- Where did you find your lost pen?
--- It was in the park ____ we went that day ____ I found it.
A.what; that B.which; that C.where; that D.when; that
答案：C.设空第一处考查定语从句,先行词为the park,将其代入定语从句中：we went to the park that day.由此可知,设空处用to which或where.设空第二处考查强调句.
