正常精液，极少见（）。

A.红细胞

B.白细胞

C.精子

D.上皮细胞

E.精母细胞和精子细胞

A plane traveled k miles in the first 96 minutes of flight time. If it completed the remaining 300 miles of the trip in t minutes, what was its average speed, in miles per hour, for the entire trip ？（）

A.A

B.B

C.C

D.D

E.E