照明变压器必须使用（）型。
A、安全
B、单绕组
C、双绕组
D、自耦变压
参考答案：C
Ted came for the weekend wearing only some shorts and a T-shirt, _____ is a stupid thing to do in such
weather. [ ]
A. this
B. that
C. what
D. which
孕妇应从妊娠第几周开始自我监测胎动？（）
A.26周
B.28周
C.30周
D.32周
E.34周
