问题
选择题
If nature does not provide man with the necessary material, it is the laboratory ____ he will turn to for it．
A．where
B．that
C．which
D．what
答案
答案：B
考查强调结构。本句结构为it is + 强调部分 + that从句，强调the laboratory，在句中作turn to的宾语，选B。