供给的基础是()
A.生产
B.消费
C.分配
D.利用
E.生产和消费
参考答案:A
为预防胎儿发生神经管畸形,孕期应补充叶酸,开始补充的时间应在
A.孕前至少1个月
B.孕后1个月
C.孕后2个月
D.孕后3个月
E.分娩前1个月
She had never been to the Great Wall before.Today she saw it the first time. [ ]
A. at
B. for
C. in
D. by