【单选题】Marine radars are used to measure _______ of ships to prevent collision with other ships,to navigate and to fix their position at sea where within range of shore.
C.
the bearing and distance
D.
the distance and advance
【判断题】JavaScript是基于事件驱动的后台脚本语言。()
【判断题】气相色谱仪进样器的作用是将液体样品瞬间气化,同时将气化样品送入色谱柱。( )
【简答题】某商品的需求曲线是Q=10-P。当价格是4时,需求量是多少(第1空)?消费者剩余是多少(第2空)?