乙类功率放大器比甲类功率放大器（）
A.输出电压高
B.输出电流大
C.效率高
参考答案：C
用所给单词的适当形式完成句子。
1.He learned it_____ (he).
2.Lesson 3 is not so_____ (playful) as Lesson 5.
3.You should send for the doctor as_____(faster) as possible.
4.The more you learn, the_____(great) knowledge you will get.
5.How heavily it rained yesterday! But today it is even_____ (heavy).
讲座收入应纳个人所得税额( )元。
A．419.05
B．550
C．570
D．613
