=>

1. Mr Nam has taught us Math for 2 years.

-> bị động HTHT chuyển sang chủ động : S have/has V3/ed

2. How long have they used this room?

-> bị động HTHT chuyển sang chủ động have/has S V3/ed?

3. They must widen this road soon.

-> bị động chuyển sang chủ động S must V

4. They can't open this door.

-> bị động chuyển sang chủ động S can't V

5. They/People can't make tea with cold water.

-> bị động chuyển sang chủ động S can't V 

6. They/People will translate this book into Vietnamese.

-> bị động TLĐ chuyển sang chủ động S will V

EX2: Turn into active

1. We have been taught Math by Mr Nam for 2 years

2 . How long has this room been used?

3. This road must be widened soon

4.This door can’t be opened.

5. Tea can’t be made with cold water.

6.This book will be translated into Vietnamese.\

Giải

1. Mr Nam has taught us Math for 2 years.

2. How long have they used this room?

3. They must widen this road soon.

4. They can't open this door.

5. They can't make tea with cold water.

6. They will translate this book into Vietnamese.