当松开油门把手，油门扳机和油门锁将返回原来的位置。此动作是由（）个独立的复位弹簧控制。
A.1
B.2
C.3
D.4
参考答案：B
____ much we dislike the idea of begging in the street, we should still show consideration
for those who are in difficult situations. [ ]
A. However
B. How
C. Whatever
D. No matter
集成化六脉冲触发组件同步电压输入后，在KC04电路端子4形成（）Hz的锯齿波。
A、400
B、200
C、100
D、50
