1. The safe is kept in the bedroom on the second floor.

2. He has worked for this non-profit organisation for five years.

3. It takes me 30 minutes to walk to school everyday.

4. This is the first time he has had such an interesting experience.

5. How about cycling to the town at the weekend?

=>
1. The safe is kept in the bedroom on the second floor.
-> bị động HTĐ is/am/are V3/ed
2. He has worked for this non-profit organisation for five years.
-> chuyển QKĐ sang HTHT, S have/has V3/ed, for + khoảng thời gian
3. It takes me 30 minutes to walk to school every day.
-> spend time Ving ~ take time to V
4. This is the first time he has had such an interesting experience.
-> this is the first time S have/has V3/ed ~ S have/has never V3/ed
5. How about cycling to the town at the weekend?
-> how about Ving? ~ Why don't we V?