The building around the corner caught fire last night. The police are now ________the matter. [ ]

A．seeing through  

B．working out

C．looking into  

D．watching over

锻炼身体的方法有：（）等练习方法。

A.重复、间歇、连续、变换、综合

B.重复、间接、直接、变换、综合

C.重复、间歇、连续、变换、综合

D.重点、间接、直接、改变、综合