Sure! Here are the answers for the questions based on the text you provided:

### Question 3: Complete each sentence with the correct form of the word given.

1. I like to speak English to people from **different** countries. (differ)
2. Speaking English with correct **pronunciation** is difficult. (pronounce)

### Question 4: Complete each of the following sentences using the cues given.

1. Noise pollution **in big cities** leads to hearing problems.
2. Lots of aquatic animals **die because of** oil spills.
3. If you **were president of your country**, what would you do to protect the environment?
4. One way to **save the environment is to use renewable energy sources**.
5. This boy **suffers** birth defects because **his parents were exposed to radioactive pollution**.

### Question 5: Put the verbs in brackets into the correct form.

36. If I see him, I **will give** him a gift.
37. If I had a typewriter, I **would type** it myself.
38. You could make better progress if you **attended** class regularly.
39. If I **knew** his telephone number, I’d give it to you.
40. If you **arrived** ten minutes earlier, you would have got a seat.
41. If he worked more slowly, he **would not make** so many mistakes.
42. I shouldn’t drink that wine if I **were** you.
43. If I **find** a cheap room, I **will stay** for a fortnight.
44. If I **had known** about the factory closing down…

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