什么是售货连续作业，其要求有哪些？

目前，在人事选拔和配置方面应用较多的能力倾向测试有（）。

A.一般能力倾向成套测试

B.鉴别能力倾向成套测试

C.感情能力倾向成套测试

D.机械倾向测试

E.文书倾向测试

Thanks to scientific research, we now have a good understanding of ______ an earthquake is and why it happens.

A．how

B．which

C．whether

D．what

在提高电动势离心泵的出力时，泵的压头会减少，而给水管道在此时的阻力却增大，所以，在选用时应按最大出力和对应于这个最大出力下的压头为准。( )

Rapid application development (RAD) systems purport to lighten the developer’s (46) by making it easy to program an application with simple intuitive steps.

RAD tools (47) the developer everything needed to construct a fully functional application quickly and easily. They make short work of modifying the developed product to (48) changes after the program is finished. Applications developed with RAD tools are constructed as they are envisioned. As an application’s real usefulness (49) , the developer armed with RAD tools should be able to (50) on new features with little fuss.

（46）是（）

A.burden

B.trouble

C.task

D.weight

《煤矿安全规程》规定，采煤机如果内喷雾装置不能正常喷雾，外喷雾压力不得小于（）MPa。无水或喷雾装置损坏时必须停机。

A、2

B、4

C、5