投掷项目的用力顺序是（）
A、自上而下
B、自下而上
C、由中间的两端
参考答案：B
4．Good news came that Nancy decided to donate blood to DanHeins, and the results of the medical tests came in: She was a___________.
A．suit
B．fit
C．match
D．Mate
中国的二元结构的基本特征是什么？
