18、对于5.2%的下降梯度,当地速为140KT时,对应的下降率约为?For gradient of 5.2%,what is

18、对于5.2%的下降梯度,当地速为140KT时,对应的下降率约为?For gradient of 5.2%,what is the corresponding descend rate to the ground speed of 120KT?

A.600ft/min。

B.500ft/min

C.750ft/min

正确答案是C