Light pollution happens. There is a change in animals' living patterns.
If.................................................
The last time Phong visited Tasmania was five years ago
Phong has......................................
The early train is scheduled to arrive in London at 10 o'clock. (arrives)
The early train..................................
It is a long time since we last met
We haven't.......................................
This is the first time I had such a delicious meal
I haven't...................................................
This is the first time he went abroad
He hasn't..........................................
She started eating when it started to rain
We have............................................
Light pollution happens. There is a change in animals' living patterns.
If..........light pollution didn't happen, there ươuldn't be change in animals' living patterns.......................................
The last time Phong visited Tasmania was five years ago
Phong has..........not visited Tasmania for 5 years............................
The early train is scheduled to arrive in London at 10 o'clock. (arrives)
The early train......arrives in London at 10 o'clock............................
It is a long time since we last met
We haven't........met for a long time...............................
This is the first time I had such a delicious meal
I haven't...had such a delicious meal before................................................
This is the first time he went abroad
He hasn't..............gone abroad before............................
She started eating when it started to rain
We have............eatten since it started to rain................................