1. What about buying energy-saving bulbs?

⇒Shall we buy energy-saving bulbs?

2. Let's use electricity economically.

⇒Why don't we use electricity economically?

3. Why don't you ask her yourself?

⇒I suggest you ask her yourself

4. What about organizing a charity event to raise money?

⇒Suggest a charity event should be organized to raise money

5. Suggest unused clothes should be collected for the victims.

⇒What about collecting unused clothes for the victims?

6. "Why not take the garbage to recycling centers?" said the local authorities.

⇒The local authorities suggested garbage should be taken to recycling centers

7."Shall we go to the English speaking club?" Andrew said

⇒Andrew suggested going to the English speaking club

8. "Why don't you put an advertisement in this local newspaper?" they said to me. 

⇒They suggested that an advertisement should be put in this local newspaper

9. Why don't you repair the electric fan, Nam?" Ba asked.

⇒Ba suggested Nam repair the electric fan

10.'Let's not tell anyone until we are certain that the report is true', said Tom.

⇒Tom suggested not telling anyone until they were certain that the report was true