下列哪一项不是水平传播
A．空气传播
B．经水传播
C．产前期从母亲到后代之间的传播
D．经食物传播
E．经媒介节肢动物传播
参考答案：C
--- Can I help you ?
--- I’d like to buy a present for my best friend, _______at proper price but of great use.
A．that
B．one
C．it
D．this
混乱天空的高积云，如高积云有几个高度，云体各异，排列无序，此时CM报（）.
A.6
B.7
C.8
D.9
--- I’d like to buy a present for my best friend, _______at proper price but of great use.