若U={1,2,3,4},M={1,2},N={2,3},则CU(M∪N)=[ ]
A.{1,2,3}
B.{2}
C.{1,2,3}
D.{4}
答案:D
Jeremy Lin __________ an unknown basketball player in New York Knicks for quite a long time. [ ]
A. used to be
B. used to being
C. is used to be
D. was used to be
在机翼表面附面层由层流状态转变为紊流状态的转捩点的位置()
A.将随着飞行速度的提高而后移
B.将随着飞行速度的提高而前移
C.在飞行M数小于一定值时保持不变