______is very important for us students to learn English well.
After decades of living under oppression, the people of the Arab world are rising up to rebel ______ their ruler.
A spokesman said, “______ it is rainy, Prince William and Kate will appear on the palace balcony at 1:25 pm for their longawaited kiss.”
______ was most shocking about the tornadoes in America was that they threatened six states and killed more than 100 persons.
The disappearance of dinosaurs made _______ the evolution and dominance of mammals on the earth.
I felt most angry about the way ______ I was treated when I was shopping.