司钻法压井时,当注入36方压井钻井液时的循环立管压力为()MPa。初始循环立管总压16MPa,终了循环立管总压力11MPa,管柱内总容积53方。
A. 12.5
B. 13.9
C. 12.6
D. 15.4
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nternational Transport Transport plays an important part in international business because goods produced have to be delivered to the buyers abroad, and the delivery of goods is to be made possible by transport services. Goods are carried by several means of transport on road or rail, by sea or air. And in recent years, combined transport which is a road-sea-rail carriage appeared. With the expansion of international trade, the container service has become popular. The use of containers provides a , highly effective form of transport . by road, rail and sea, Basically , orabout 98% of world trade is carried out by sea transport.Besides transport by sea, road, or rail, nowadays in order to speed up delivery, carriage by air international has also become popular. Today carriage by air has become popular because it can speed up delivery.
A. 正确
B. 错误
当()时,进程从执行状态转变为就绪状态。
A. 进程被调度程序选中
B. 时间片到
C. 等待某一事件
D. 等待的事件发生
水稻“三化一管”栽培模式主要内容是:()、()、()、()。