—Who is it?
— ______. I took this photo when I was 4.[ ]
A. I
B. Me
C. Mine
D. Myself
答案:B
如图所示的四种现象中,属于光的直线传播的是[ ]
A.
B.
D.
血浆置换时通常认为,置换1个血浆容量,血浆去除率为()。
A.65%
B.75%
C.85%
D.95%
E.98%