问题补充：
It was in the lab was newly built they carried out the experiment.
A. that; which
B. that; that
C. where; that
D. which; where
答案：
A. that; which
(答案→)B. that; that
C. where; that
D. which; where
解析：考查定语从句和特殊句式之强调句。强调句结构为：It + is/was + 被强调部分 + that/who(对主语强调) +（主语）+ 谓语 + ……。判断是否为强调句可用简化法和还原法：去掉It is/was和that/who；如果假设的被强调部分能与后面的部分构成完整的一句话则为强调句。本句假设为强调句, 则首先要找出被强调部分。因为第二空后为完整的句子，假设in the lab为被强调部分，正好可还原为they carried out the experiment in the lab.故第二空填that（强调句中的that）； 第一空如果填that、which均可作为关系代词与was newly built构成定语从句修饰lab（先行词）并且that、which正好作从句的主语。而where是关系副词只能在从句中作状语，因从句缺主语故排除C。综上所述，正确答案为B。
