下列著名战争中不是发生在战国时期的是[ ]
A．桂陵之战
B．马陵之战
C．长平之战
D．城濮大战
答案：D
——Excuse me, Professor Smith, I was wondering if I could leave a quarter earlier today.
——____.
A．Nothing the matter.
B．Sure, go ahead
C．Oh, why not?
D．No trouble at all
N2受体兴奋可引起（）。
A．瞳孔扩大
B．支气管平滑肌松弛
C．腺体分泌减少
D．胃肠道平滑肌收缩
E．骨骼肌收缩
