—How about your trip to Hainan
— It couldn't have been ______. Sometimes I went swimming in the sea; sometimes I lay on the sand.

A. so well



B. as bad
C. better



D. worse

指示空速（IAS）与校准空速（CAS）之间的关系是（）.

A.IAS修正了气源误差及非线形误差后为CAS，故CAS是更精确的IAS；

B.IAS修正了空气密度随高度的变化后为CAS，故CAS是更精确的IAS；

C.IAS修正了空气的可压缩性系数为CAS，故CAS是更精确的IAS；

D.IAS修正了温度误差为CAS，故CAS是更精确的IAS。