DIRECTIONS: Select the best topic sentence. 1. Select the best topic sentence. a. b. It is easy to build a birdhouse if you follow these five steps. Birdhouses are nice decorations. 2. Select the best topic sentence. You must be 18 years old to vote in the United States. The voting age should be lowered to 16 years old in order to get more young adults interested and involved in the political process a. b