don't stop him doing what he wants

=> Let him do what he wants.

we started cooking for the party for hours ago

=> We have been cooking for the party for hours.

she didn't say a word as she left the room

=> She left the room without saying a word.

it's pointless to ask him for money

=> There's no point in asking him for money.

we couldn't swim because the sea was rough

=> The rough sea prevented us from swimming.

mary finished her essay in two hours

=> It took Mary two hours to finish her essay.

3. Tom has been ill for three days

1.It's the first time I have seen a dirtier-looking dog.

1 Viết lại câu sao cho nghĩa ko đổi:

1. I have never seen a dirtier-looking dog.

⇒It's__the first time I have seen a dirtier-looking dog.__

2. Mary rang hours and hours ago.

⇒It's___hours and hours since Mary rang________

3.Tom is ill. He became ill three days ago.

⇒Tom__has been ill for three days_______

2. Cho dạng đúng của động từ trong ngoặc (chia thì)

When I (leave)___left __ the house this morning, it (rain)__rained__very hard.

man has never had such efficient servants as computer

-computer is the most effecient servents man has had

i have been to the ballet before

-it is the first time I have been to the ballet

jonh and mary moved to endinburgh twenty years ago

-it is 20 years since John and mary moved to endinburgh 

mary rang hours and hours ago

-it is hours and hours since Mary rang

ha hasn't laughed so much for ages

-it's ages since Ha last laughed

the last time i was aboard was in the summer of 1978

-i haven't been abroad since the summer of 1978

the editor last written to mai for a month

-the editor last wrote to Mai a month ago

ly's father stated to stop smoking last year

-ly's father has not smoked since last year

i have learned english for four year

-we started learning E for four year

she started to learn english 8 years ago

-it's 8 years since she started to learn E

tom is ill. he became ill three days ago 
tom has been ill for 3 days