We're in class. You'd better not _______. [ ]
A. talk
B. talking
C. talked
D. to talk
答案:A
当采用钨极氩弧焊焊接镍基合金时,应选用()电源。
射频识别卡属于()。
A.IC卡
B.磁卡
C.身份识别卡
D.复合类卡