important qualities of a good son or daughter? have these qualities changes or remained same over time in your culture..

The reason is good: 'It should be helpful'. and then need some arguments. why 'helpful' is the good qualities for good son or daughter. the example doesn't mean something.

Don't forget the 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...).

and follow this user who got 29 in speaking and had good arguments:
http://www.testbig.com/users/bigzee
http://www.testbig.com/question/thank-you-letter

There are nothing wrong with the examples. The thing is that you need to give arguments why 'helpful' is the quality of a good daughter/son.

You should say something like:

Suppose my mother was ill, then i should take care of her for whatever I can like by making tea and snacks. If I leave her alone and enjoy outside with friends, no body will think I am a good daughter.