瘿气（甲亢）肝火旺盛证，治疗应首选的方剂是（）
A．逍遥散合二陈汤
B．龙胆泻肝汤
C．天王补心丹
D．生脉散加味
E．安神定志丸
参考答案：B
Yesterday I went to buy a computer. There were so many models for us ________ in the shop that I was at a loss which to buy.
A．to be chosen
B．to choose
C．to choose from
D．for choosing
如图所示，直线a为电源的U-I图线，直线b为电阻R的U-I图线，用该电源和该电阻组成闭合电路时，电源的输出功率和电源的效率分别为
A．4W、33.3％
B．2W、33.3％
C．4W、67％
D．2W、67％
