pSS患者类风湿因子的阳性率为()
A.21%
B.32%
C.43%
D.62%
E.55%
参考答案:C
19. Russia is a country which extends across _____ .
A.Asia
B.Europe
C.Asia and Europe
D.Africa
“送奶线路”难以实现多家零售店用一辆车的联合运送。