排球接发球训练应多采用（）的练习手段和方法，以克服疲劳和不认真。
A.强制
B.自发
C.合作性
D.对抗性
参考答案：D
69. With the guide leading the way, the visitors were able to travel through the forest not by air but _____ foot.
A．by
B．on
C．in
D．with
银翘散与桑菊饮的组成药物中均含有
A．杏仁B．荆芥C．薄荷D．淡豆豉E．金银花
