我国公安机关的专政职能是专门用以对付敌对势力、敌对分子和严重刑事犯罪分子的。 ( )
参考答案：对
The ____________ shoes were covered with mud, so I asked them to take them off before they got into __________ car.
A．girl’s; Tom’s
B．girls’; Toms’
C．girls’; Tom’s
D．girl’s; Toms’
下述试剂中纯度最高的是（）
A．LR；
B．AR；
C．GR；
D．CP
