若x2+ax+9=(x+3)2,则a的值为[ ]
A.3
B.±3
C.6
D.±6
答案:C
He offered the information the police needed and deserved _______.
A.rewarded
B.to reward
C.being rewarded
D.rewarding
某2个月孕妇,出现失眠、健忘、舌炎等症,经实验室检查为巨幼红细胞贫血,被诊断为营养缺乏症。
妊娠期该营养素供给量是()。
A.400μg
B.600μg
C.1.2mg
D.25mg
E.100mg