某事

Have you ever done sth.?

你曾经做过某事吗？

It's the …time that sb. have done sth.

这是某人第几次做某事。

Ought to have done sth., should have done sth.

表示本应该做某事，而事实上并没有做。

You shouldn't have done sth.

表示"你本不该做某事的"

Shouldn't have done sth.

本不应该做某事。

Be said, etc to have done sth.

据说某人做了某事。

Would like to have done sth.

表示"本来想做某事"。

Ought to have done sth, should have done sth

本应该做某事，而事实上并没有做。

Have effect on sth.

对某事/物产生效果

Have no right to do sth.

没有做某事的权利

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。