下列属于茎的异常维管束的是（）。

A.牛膝

B.商陆

C.何首乌

D.甘松

E.鸡血藤

A disk with a horizontal line through its center，equivalent to the summer load line，is called the（）.

A.deadrise mark

B.maximum allowable draft mark

C.plimsoll mark

D.tonnage mark