1. I've never seen such a wonderful computer before.

⇒This is the first time I have seen such a wonder computer

2.She started studying English seven years ago. 

⇒She has studied English for 7 years

3. I haven't seen him for two weeks. 

⇒It's 2 weeks since I last saw him

4. I've never eaten such a delicious cake before.

⇒This is the most delicious cake I have eaten

5. They haven't gone swimming since 2005.

⇒The last time they went swimming was in 2005

$cho ctlhn nha$

IV.

1. This is the first time I've seen such a wonderful computer.

2. She has studied English for seven years.

3. It's been two weeks since I saw him.

4. This is the most delicious cake I have eaten.

5. The last time they went swimming since 2005.