____________ pollutants in the air cannot be seen with our naked eyes, we don’t realize the sources of the increasing pollution level.

A. in the countryside

B. in cites

C. in poverty

D. in slum

A. made rural areas develop along with urban ones

B. made urban areas develop faster than the average

C. mainly contributed to the country’s GDP

D. promoted the country’s economy twice as fast as before

A. For we have got a few minutes to wait for the train, let’s have a cup of coffee.

B. Despite we have got a few minutes to wait for the train, let’s have a cup of coffee.

C. Unless we have got a few minutes to wait for the train, let’s have a cup of coffee.

D. Since we have got a few minutes to wait for the train, let’s have a cup of coffee.

A. by

B. in

C. to

D. for

A. She just lives six doors away, where is very handy.

B. She just lives six doors away, what is very handy.

C. She just lives six doors away, which is very handy.

D. She just lives six doors away, for which is very handy.

A. are losing

B. because

C. which

D. urbanization

A. was driven

B. green move

C. physical

D. concerns about