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Hi.
1. Are the commas placed correctly? Could I not use the last comma?

The committee members, associate members, and adult volunteers, are all volunteers.

2. Are the commas placed correctly?

They gave up hundreds of hours of their time, and most of this weekend, to help us make this a reality.

3. Do we have to place a comma after these one syllable adverbs?

They are good in their work; thus, they were offered promotion
They finished their school. Then, they went on to a beach to get some suntan.
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These are correct:

The committee members, associate members, and adult volunteers are all volunteers.

They gave up hundreds of hours of their time and most of this weekend to help us make this a reality.

They are good in their work; thus, they were offered promotion
They finished their school. Then they went to a beach to get some suntan.
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Hi. Why did you put a comma after the "thus" in the first sentence, and not use a comma after the "Then" in the second sentence. I must say that the two sentences are different in structure.

My sentences with your correction:

They are good in their work; thus, they were offered promotion
They finished their school. Then they went to a beach to get some suntan.

Would you still use a comma after "thus" here?

They are good in their work. Thus, they were offered promotion

Thank you.
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I would still use a comma. 'Thus' in both cases refers back to the previous clause ('they are good; therefore...'). 'Then', however, just marks a time sequence; 'then' refers to the beach-going, not the school-finishing.
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