Other sentences need to be made more clear, more interesting, or both. Rewrite each topic sentence so that it is an effective topic sentence for a paragraph. You may make up any information you need or use reference books to find out more information.
Some people work too hard.
An hourglass measures time. Most birds fly, but not the ostrich. I will tell you some interesting information about gender issues. A great many people are extremely afraid of every snake that they ever see, but everyone should be made aware of the fact that, indeed, not all snakes are dangerous and in fact most snakes are beneficial to people. The sitar is a stringed instrument from India.