It’s too hot. —Let’s open the windows to allow the air to_________.

s population is expected to increase to about1.5 billion, ____ it will start to decline slowly.

Ane got an “A” in the Maths test.— . She works the hardest in our class.

tothe world, the dance “Gangnam Style” has gained greart great popularity.

With April 18’s railway speedup, highway and air transport will have to compete with ________ service for passengers.