词形变换。 1. The ________ Sunday in May is Mother's Day. (two) 2. The teacher told us not to go ________ alone in the river. (swim) 3. I want to be an ________ when I grow up. (invent) 4. Shouting in public is ________. (polite) 5. We are ________ about the good news. (excite) 6. The ________ we exercise, the healthier we'll get. (much) 7. It is ________ that many drinks are bad for our health. (say) 8. As a student, we should listen to teachers ________. (careful) 9. It is very cold outside. You had better ________ on a coat. (put) 10. He told me he ________ go to the Great Wall tomorrow. (will)