VOA慢速英语:Scientists Design Chips to Act Like Human Organs

1. It also can take a lot of time.

a lot of 许多
例句：He collected a lot of valuable stamps. 
他收集了许多有价值的邮票。 

2. In the case of a heart, it would be representing the heart muscles and be able to show contractibility and regular beating of the heart muscles.

in the case of 至于…， 就…来说
例句：In the case of uncertainty, the definition of rationality becomes problematic. 
在非确定型的情况，合理性的概念却难以确定。 
be able to 能够
例句：We must be able to stay impartial at all times. 
我们必须经常保持公正的态度。  
 
3. They copy the real function or duties of the human stomach and intestine, moving when breaking down food.

break down 失败; 划分（以便分析）; 损坏
例句：The artificial distinctions of race also break down. 
人为的种族差别也就会消除。 

4. Drugs are added to the tiny organs for testing through instruments known as micro-tubes.

add to 增加，加强
例句：Politics will add to the policy complications.
政治也将加大政策的复杂性。