从1~9这9个自然数中任取一个,是2的倍数的概率是______.
从1~9这9个自然数中,2的倍数有:2,4,6,8,共4个,
任取一个是2的倍数的概率是:49.
“ What is your name?” “______”
A.My name is Jim Green
B.My name is Green Jim
C.Jim Green is I
D.This is Green Jim here.
某地乙肝发病率通常在4%左右,为降低该地区乙肝对人群健康的危害,拟普遍接种乙肝疫苗,已知该疫苗的效果指数为10。该疫苗的保护率为()
A.90%
B.50%
C.89%
D.99%
E.95%