One type of community work you want to take part in.

24 in 30

You may remove the first example. It takes too much time. Try this pattern for Q1-Q2:

first 1-2 sentences: introduction. my opinion: A or B. agree or disagree. about 5-10 seconds

First, reason 1 (1 sentence) + why reason 1 (some arguments. 1-2 sentence) + a small conclusion for reason 1(like advantages of reason 1 or comparisons if not reason 1, 1-2 sentence). // about 15 seconds

Second, reason 2 (1 sentence) + why reason 2 (some arguments. 1-2 sentence) + a small conclusion for reason 2(like advantages of reason 2 or comparisons if not reason 2, 1-2 sentence). // about 15 seconds

Conclusion: Don't need a conclusion. (you can have one only when you don't have something to talk about)

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An example (Eating at home or restaurant) for First:
First,reason 1 (1 sentence: Eating at home can save money) + why reason 1(some arguments. 1-2 sentences: I can prepare cheaper food from food market; I don't need to drive or take a bus to reach the restaurant;) + small conclusions ( 1-2 sentences: with the money I saved, I can buy a good book to read; I can use the money for a trip...).