Weare()howanerrorlikethiscouldhavehappened.
A. searching
B. researching
C. surveying
D. investigating
下列哪些试剂是绝缘油击穿电压检测需要使用的()。
A. 丙酮
B. 石油醚
C. 乙醇
D. 氢氧化钾
Wesenthimourbest()forhisbirthday.
A. wishes
B. sayings
C. greeting
D. cheers
Ithinktheyare()Whichofthefollowingisnotcorrect?
A. Briton
British
C. English
D. Englishmen