It was his wife___ left him without saying goodbye.
A.who
B.which
C.when
D.in which
答案:A
临床上铸造支架多采用钴铬合金,其熔点是
A.850~930℃B.1680℃C.950~1250℃D.1290~1425℃E.2500℃
GPS的安装位置受地域的限制同时要远离电子产品但是可以在天线的主瓣内。()