4. None but scientists are competent to decide whether or not vivisection is necessary to science.
5. If necessary to science, vivisection should be practised only when necessary.
6. A debating society is a help in education.
7. The American Revolution is an uninteresting theme topic.
8. The American Revolution is not an uninteresting theme topic.
[Other sentences can easily be suggested by students or teacher.]
Theme.—Develop one of the following topic sentences into a paragraph of contrast,—200 words.
1. There is a difference between knowing a thing, and being able to tell it.
2. Outside the wild winds were rioting; within all was cheer.
3. I saw an old man holding his granddaughter in his arms.