Learn to express something with Past Perfect Tense.

The present and past perfect tenses both belong to the perfect tense.

现在完成时和过去完成时都属于完成时态.

An aurora borealis sends ribbons of yellow - green light through the sky over northern Canada.

北极光在自然界的模式。一个北极光发送黄绿色带灯光通过加拿大北部上空。

The distribution characteristic of auroral electrojet in AZS, is helpful for the studies of F layer and magnetosphere coupling in polar region and aurora dynamics.

了解了极光电集流在南极中山站的分布特征，有利于极区电离层和磁层耦合及极光动力学的研究。

The Alfv é n solitary waves, accompanied by the parallel electric field, take an important part to accelerate the charge particles. This provides a possible physical mechanism for the acceleration of polar aurora in the auroral region.

Alfv啨n孤波携带有平行电场，它对带电粒子的加速有重要作用，这给极光粒子加速提供了一种可能的物理机制。

The S & P 500 is down 50 % from its peak, and indexes around the world have cratered.

标准 普尔 500指数迄今已从高点回落50%左右, 世界各地的股指也纷纷下跌.

Artillery cratered the road.

大炮把路面轰得坑坑洼洼.

I further cratered my chin as an adult.

成年后,我又在下巴上留下了痕迹.

Aurora felt the opium haze enfold her

奥萝拉感觉自己被笼罩在鸦片烟霾中。

The Expressions of Aurora A in Human Esophageal Squamous Cell Carcinoma

食管鳞状细胞癌组织中TPX2的表达

AURORA: At least you found the great love of your life.

奥柔拉：至少你生命中找到了挚爱。

So if you see an aurora, keep your ears open.

所以，如果你看到极光，记得竖起耳朵倾听。

Effect of Aurora A on Biological Phenotypes of Prostate Cancer Cells

Aurora A表达对人前列腺癌细胞生物学行为的影响

The people we lost in Aurora loved, and were loved.

在奥罗拉，我们失去了我们所爱和爱着我们的人。

Aurora: Well, call me if you change your mind.

恩，改变主意后打电话给我。

Study of the Detection Mode of Upper Atmospheric Wind Field Based on Lorentzian Profile Aurora

基于洛伦兹线型极光的上层大气风场探测模式研究

Application of AURORA WMS in Shooting Range Command and Control System

AURORA WMS在某靶场指挥控制系统中的应用

Aurora was never bored with this kind of cultural exchange between Germany and China.

Arora对于中德两国的文化交流一直是这样乐此不疲。

Expression and significance of Aurora B in normal endometrium and endometrial carcinoma

Aurora B在子宫内膜和子宫内膜癌组织中的表达及其意义

I also went to the library to find out about the aurora.

我还去了图书馆查极光的资料。

At his distribution center in Aurora, one wall is temporary to allow for expansion.

在位于奥罗拉的销售中心，随时都可以进行扩张。