She is continually inviting her friends to our room which makes it impossible for me to do the necessary study.

她经常邀请她的朋友到我们的宿舍，这使我无法正常学习。

Or, to try to do something before you've done the necessary preparation.

或者，在你做必要的准备之前尝试做一些事情。

Leave it to me – I’ll do the necessary.

【necessary】交给我吧，我会做必要的事。

" To cover, " here, means to do the necessary work, to finish or complete the work.

“覆盖”在这里的意思是做必要的工作，完成或完成工作。

Luckily, doing the necessary math on any normal computer would literally take years of trial and error.

但要用这些数学方法计算私钥，传统计算机可能要耗费数年。

The multiplier tells us by how much their employment has to be increased to yield an increase in real income sufficient to induce them to do the necessary extra saving, and is a function of their psychological propensities.

乘数告诉我们他们的就业必须增加多少才能使实际收入增加到足以促使他们进行必要的额外储蓄，并且是他们心理倾向的函数。