问题
选择题
It was from May 1 to October 31,2010____________the World Expo 2010 Shanghai will be held, _____________is a great event for the Chinese people.
A．when; that
B．that; when
C．which; when
D．that; which
答案
答案：D
第一空that构成强调句型；第二空which引导非限制性定语从句，并充当其主语。
±US计算出，而可信区间可以由
计算出