1. We'd like to buy some oranges. (改为一般疑问句)

2. This French book must be Mary's. (改为否定句)

3. It seems that she has changed a lot. (改为同义句)

4. Why don't you join an English club to practice speaking English? (改为同义句)

5. It is so hard that we can't understand the sentences. (改为简单句)

1、1. Would you like to buy some oranges?

2. This book can't be Mary' s.

3. She seems to have changed a lot.

4, Why not join an English club to practice speaking English?

5. It is too hard for us to understand the sentences.