下列程序的运行结果是______。 main()int x=1，y=2，z=3；p

Everyone will have to ______ a test before they are admitted to the university.

A．come through

B．look through

C．pull through

D．go through

6月26日是“国际禁毒日”，下列关于毒品的描述错误的是（　　）

A．毒品损害人的大脑和心脏

B．毒品具有成瘾性，一旦染上很难戒除

C．少量吸毒能增强人体免疫力

D．青少年要提高警惕，自觉抵制毒品

One Friday, we were packing to leave for a weekend away____ my daughter heard cries for help.

A．after

B．while

C．since

D．when

请阐述地膜覆盖黑色马铃薯丰产栽培技术的田间管理有哪些注意事项？

如何区分设备故障与设备事故？