复合预混合饲料用混合机的混合均匀度变异系数不大于（）；

A、1%

B、3%

C、5%

D、7%

When a rescue vessel approaches a lifeboat in heavy seas，the person in charge of the lifeboat should（）.

A.tie up to the rescue vessel

B.transfer only those personnel who are not seasick

C.wait for calmer weather before transferring personnel

D.transfer all personnel immediately