问题描述：
复合句You’d better begin the preparations now and the most important thing is to chec
You’d better begin the preparations now and the most important thing is to check ______ the laboratory can
be used for the tests.A.where B.when C.what D.that
为什么选B
You’d better begin the preparations now and the most important thing is to check ______ the laboratory can
be used for the tests.A.where B.when C.what D.that
为什么选B
问题解答：
我来补答展开全文阅读