giúp mk với

I'd be happy to help you with these exercises. Here are the answers and explanations: **Question 20:** People are always advised to **cut down on** smoking because of its harm to their health. Explanation: "Cut down on" is a phrasal verb that means to reduce or decrease something (in this case, smoking). **Question 21:** You have to take the full **course** of your antibiotics even if you feel better, otherwise your illness will simply return. Explanation: "Course" refers to the entire treatment or regimen of medication. **Question 22:** 500 years ago, the average human **lifespan** was about 40 years. Explanation: "Lifespan" refers to the length of time a person lives. **Question 23:** She wishes that we hadn't sent her the candy yesterday because she's on a **diet**. Explanation: "Diet" refers to a specific regimen of food intake for weight loss or health reasons. **Question 24:** He sent his children to the park so that he could have some **peace and quiet**. Explanation: "Peace and quiet" is an idiomatic expression that means a state of calmness and silence. **Question 25:** In the wake of increasing food poisoning, many consumers have turned to vegetables grown **organically**. Explanation: "Organically" refers to the method of growing plants without using synthetic fertilizers or pesticides. **Question 26:** Obesity is a medical condition in which excess body fat has **accumulated** to the extent that it may have a negative effect on health. Explanation: "Accumulated" means to gather or collect over time. **Question 27:** The controller of the body is the **nervous** system. Led by the brain and nerves, it allows us to move, talk and feel emotions. Explanation: The nervous system is the system that controls the body's functions. **Question 28:** A healthy **balance** between work and play ensures that everyone has a chance to enjoy their lives. Explanation: "Balance" refers to a state of equilibrium or harmony between two or more things. **Question 29:** I've been a night owl **staying** up late for years, hitting the sheets anytime between 12 and 3 a.m. Explanation: "Staying" is the correct verb to use in this sentence, as it indicates the act of remaining awake late at night. **Question 30:** The symptoms of depression can include poor **appetite** and weight loss. Explanation: "Appetite" refers to the desire to eat. **Question 31:** The virus affects the body's immune system so that it cannot fight **infection**. Explanation: "Infection" refers to the invasion of the body by a foreign substance, such as a virus or bacteria. Let me know if you have any questions or need further clarification on any of these answers!