What makes your voice _______ louder ? [ ]
A. sounds
B. sounded
C. sound
D. sound like
答案:C
(文)已知函数y=f(x),x∈{1,2,3},y∈{-1,0,1},满足条件f(3)=f(1)+f(2)的映射的个数是( )
A.2
B.4
C.6
D.7
治麻疹初起兼表证之咳嗽,下面哪项是正确的()
A.燥湿止咳
B.收敛止咳
C.温肺止咳
D.润肺止咳
E.以上均不对