早产儿生后添加维生素D制剂的时间是（）
A.1周
B.2周
C.3周
D.4周
E.3个月
参考答案：A
“水火相济”是指（）
A．肝与肾
B．肺与脾
C．肺与肾
D．心与肾
E．肝与脾
I’ve heard that the wood tower was built more than 1,000 years ago, so I think it is worthy ________．
A．visiting
B．to visit
C．being visited
D．to be visited
