This weekend we’re going to Beijing to attend a summer camp and we’ll visit the Bird Nest_______we get there.
Outside my office window there is a fire __________ on the right.
It's said that a prisoner has escaped __________ the prison.
The bird escaped __________ 、
Human __________ is much more complicated than that of atoms, liquids or planets.
It is the government that __________ the country through the difficulties.