Police _(调查)the disappearance of two children these days (look)
问题描述:
Police _(调查)the disappearance of two children these days (look)
答
have been looking into these days提示要用现在完成时,因为调查还在进行之中,并没有停,所以要用进行时,合起来就是现在完成进行时.