问题
How about the pollution in the countryside?－Luckily, it’s not as serious as _______ in the big cities.
A:that
B:it
C:one
D:those
B:it
C:one
D:those
正确答案是：
同类题型
Scientists are working hard to make _______ possible for people to live on Mars in the future.
He made another wonderful discovery, ______ of great importance to science.
The students stay _____ home _____ Sundays.[ ]
We have a lot of rules at my house.—. How unlucky we teenagers are! [ ]
It shows what has happened the forests of the USA in the last 350 years.[ ]