按要求画好电路图，再根据电路图，连接出对应的实物图。
电路要求：
(1)L1与L2组成并联电路。(2)S1控制L1，S2同时控制L1与L2。
参考答案：
John and I＿＿＿friends for eight years.We first got to know each other at a Christmas party.But we＿＿＿＿＿ each other a couple of times before that.
A．had been； have met
B．have been； have met
C．had been； had met
D．have been； had met
胸骨左缘第二肋间闻及收缩期杂音。应考虑为()
A．主动脉辦狭窄
B．肺动脉辦狭窄
C．二尖辦狭窄
D．三尖辦狭窄
E．动脉导管未闭
