我不十分确定导致体重增加的原因。
A.I’M NOT EXACT SURE WHAT CONTRIBUTED IN THE WEIGHT GAIN.
B.I’M NOT EXACTLY SURE WHAT CONTRIBUTED TO THE WEIGHT GAIN.
C.I’M NOT EXACT SURE THAT CONTRIBUTE TO THE WEIGHT GAIN.
D.I’M NOT EXACTLY SURE THAT CONTRIBUTES TO THE WEIGHT GAIN.
正确答案是B