问题补充:
At the present time, more singing stars to be difficult to work with.
A. say
B. have said
C. are said
D. were said
答案:
A. say
B. have said
(答案→)C. are said
D. were said
解析:句意:目前,据说很多唱歌的明星很难共事。Be said to是固定用法,意思是据说,且根据时间状语At the present time,故用一般现在时,选C。