某元素X的气态氢化物的化学式为XH3,则X的最高价氧化物的水化物的化学式为[ ]
A.H2XO3
B.HXO3
C.HXO
D.H2XO4
答案:B
We all wish to do the job better with ______ time and ______ people since we don't have much money. [ ]
A. 1ess, fewer
B. fewer, less
C. fewer, more
D. more, fewer
药品不良事件指用药期间发生的任何不利的医疗事件,该事件一定与药品存在因果关系。