1.food chain 食物链

Officials also say it never entered the human food chain.
官员称它从未进入人类的食物链当中。

Mercury accumulates as it works its way up the food chain.
汞会随着食物链上的食物传递而积聚。

2.made up of 由…组成，由…构成

The fill made up of basket loads of different colored clay.
填充物由一篮一篮不同色的粘土形成。

The brain is made up of cells in a certain arrangement.
人脑是由细胞按一定的排列方式组成的。

3.suck up 吸收

Another way would be growing algae in the ocean to suck up carbon dioxide.
另外一种办法是可以通过在海洋里种植藻类来吸收二氧化碳。

The nutrients feed algal blooms, which suck up the oxygen in the water.
这些营养养育了大量藻类，这些藻类吸收水中的氧气。

4.work out 解决；作出；锻炼

Negotiators are due to meet later today to work out a compromise.
谈判人员定于今天晚些时候进行会谈，商定一个折中方案。

It took me some time to work out what was causing this.
我花了一些时间才弄清此事的起因。