例句：As I look back at the world I left, it is all so clear to me.
我回頭看著身后的世界，一切是如此清晰。

2.by that time 到那時；到那個時候；等到那時候

例句：There seemed no obstacle to arresting Mr Mladic, but by that time the authorities appeared to have lost track of him.
這樣看起來逮捕姆拉迪奇似乎沒有什么困難了，但是在那個時候權力機關卻失去了他的行蹤。

3.take a few tentative steps 小心翼翼地邁開步子

例句：We push ourselves up, we take a few tentative steps, then we fall down.
我們先抬起雙腳，小心翼翼的邁開步子卻又接著跌倒。

4.samples of ...的樣品

例句：The bacterial endotoxin tests of 3 batches of samples were all up to the standards.
3批樣品細菌內毒素檢查均符合規定。