1.

What did Tim think?

He thought (that) Roger had given up smoking.

2.

What happened in the summer?

In the summer, Roger took up the habit again.

3.

What does Tim warn Roger?

Tim supposes (that) Roger will be coughing and wheezing again in the mornings. 

4.

What will happen next month?

Next month Roger's office is going non-smoking. 

5.

What does Roger complain about?

He complains about former smokers being so anti smoking.