双代号网络图的基本要素不包括()。
A.工作
B.节点
C.时间坐标
D.线路
参考答案:C
During the tourist season, there are many people wandering in this city to see the old castles _____ in the sixteenth century.
A.to be built
B.being built
C.having been built
D.built
秦汉三国时期将武艺做为竞技项目来鼓舞士气娱乐军士,出现了()、()项目。
A.手搏
B.相扑
C.角抵
D.散打