1. b 2. a 3. b 4. b 5. a 6. b
1. Let me jot down your phone number before you leave.
2. We come to the margin of the wood.
3. sat there and tried to mull over things in my mind.
4. A good teacher should not only impart knowledge to their students but also should encourage them to come to grips with problems in a certain area.
5. 他试图想象他祖父的样子。