鸟类的生殖和发育过程伴随着复杂的繁殖行为，下列繁殖行为不属于鸟类的是[ ]
A．筑巢
B．哺乳
C．求偶
D．育雏
答案：B
______ is to be awarded the highest award at this evening’s meeting.
A．Both the director and the writer
B．Both of the director and the writer
C．The director and the writer
D．The director and writer
飞机做大坡度盘旋时，为保持高度，（）需增加带杆量。
A.用以保持机头沿转弯方向运动
B.为补偿升力垂直分量的损失
C.为补偿升力水平分量的损失
