Maggie ____the floor when she _____the door bell ring.
A:was sweeping … heard
B:swept … heard
C:was sweeping … was hearing
D:swept … was hearing
第1题:
A.CY-CY
B.CY-DOOR
C.DOOR-CY
D.DOOR-DOOR
第2题:
第3题:
下列因素中,对横向静稳定性起增稳作用的有 Which of the following factors can increase the lateral static stability.
A.上反角 dihedral angle
B.下反角 anhedral angle
C.后掠角 swept-back angle
D.前掠角 swept-forward angle
E.上单翼 high wing
F.下单翼 low wing
第4题:
第5题:
下列因素中,对横向静稳定性起增稳作用的有 Which of the following factors can increase the lateral static stability.
A.上反角 dihedral angle
B.下反角 anhedral angle
C.后掠角 swept-back angle
D.前掠角 swept-forward angle
E.上单翼 high wing
F.下单翼 wing