1.food chain 食物鏈

Officials also say it never entered the human food chain.
官員稱它從未進入人類的食物鏈當中。

Mercury accumulates as it works its way up the food chain.
汞會隨著食物鏈上的食物傳遞而積聚。

2.made up of 由…組成，由…構成

The fill made up of basket loads of different colored clay.
填充物由一籃一籃不同色的粘土形成。

The brain is made up of cells in a certain arrangement.
人腦是由細胞按一定的排列方式組成的。

3.suck up 吸收

Another way would be growing algae in the ocean to suck up carbon dioxide.
另外一種辦法是可以通過在海洋里種植藻類來吸收二氧化碳。

The nutrients feed algal blooms, which suck up the oxygen in the water.
這些營養養育了大量藻類，這些藻類吸收水中的氧氣。

4.work out 解決；作出；鍛煉

Negotiators are due to meet later today to work out a compromise.
談判人員定于今天晚些時候進行會談，商定一個折中方案。

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