Unit 16 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 17 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 18 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 19 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 20 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 21 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 22 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 23 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 24 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 25 1. Words to learn 2. Structure 3. Listening Comprehension 4. Close reading Unit 26 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 27 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 28 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 29 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading Unit 30 1. Words to learn 2. Structure 3. Listening comprehension 4. Close reading 参考答案