Some students prefer to study or work on difficult class assignments early in the morning. Other students prefer to do this type of work in the evening. Which do you prefer and why?

22 in 30

You seems to have a lot of talk in the second reason. You need to keep 'a big map' in your mind:

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)

-----------------------------------------
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...).
----------------------
for one reason, you may have about 7 sentences. Not more.