棉花同一植株上不同部位棉铃大小的一般规律是（）

A、靠内侧重

B、外围的重

C、顶端的重

D、内外围没有差异

During the required periodic abandon ship drill aboard a ship，each person not assigned duties in the muster list is（）.

A.instructed in the use of portable fire extinguishers

B.shown a video demonstrating lifeboat launching

C.instructed in the use of life jackets

D.not required to attend the boat drill