Here are the completed sentences with the appropriate forms of the words provided:

17. We aim to help the **poor** families.
They're too **poor** to buy shoes for the kids.
They provided food and shelter for **the poor**.

18. Energy-saving bulbs should be used to save **electricity**.
Let's have an **electrician** repair the **electric** iron.

19. Now we'll be able to live in **luxury** for the rest of our lives.
She stretched **luxuriously** on the bed.

20. The **consumer's** main concern is the quality of a new product.