I can still remember that it is since the 1990’s, _____ we began to use cell phones,_______ the number of mobile users has greatly increased.
— Why is the librarian staring at me? — You _____ to read aloud in the reading room.
_____ Li Ming and Xiao Fang, there were also many other students attending the lecture.
The number of _____ species increases every year with their natural habitats disappearing.
________ of the land in that district(地区) _______ covered with trees and grass.
-How was your final exam, Tom? -I’m sorry, dad. I failed and only thenthe importance of studies.