It has been announced by our provincial government that another two medical teams will be sent to _______ the injured people in the severe earthquake.

A．join to

B．join in

C．take part in

D．attend

公安机关督察机构设督察长，由( )担任。

A．同级公安机关领导成员副职

B．同级公安机关主要负责人

C．同级公安机关行政首长

D．同级国家行政机关特派员