沙尘暴源区属于( )。
A.需特殊保护地区 B.环境保护区C.社会关注区 D.生态敏感与脆弱区
参考答案:D
.Mr.Smith was_________ to be a doctor but he became a teacher when he grew up.
A.demanded
B.supposed
C.suggested
D.agreed
分析中国电子商务支付体系的结构及实现原则。