下列句子不属于宾语前置句的一项是（ ）

I heard a student killed his mother cruelly.– So did I. It has ____a serious problemabout the education system in China.

Do you know sound travels very fast　一Yes. Butlight travels _________ sound.

When I try to find _______ that prevents so many people from taking part in the program,it seems to me that there are two main causes.

17．I’m ____a diet, since I put ____ weight easily