下列语句是命题的是[ ]
A.p(x):x2-1=0
B.q(x):5x 是5 的倍数
C.三角函数是周期函数吗?
D.对所有整数x,5x-1 是整数
答案:D
皮损愈后遗留永久性秃发的是:
A.白癣B.黄癣C.圆癣D.足癣E.阴癣
If you receive a bunch of roses on Valentine's Day, Do you know what hidden meaning is _______ to it? [ ]
A. put
B. introduced
C. attached
D. tied