Space exploration has been made ______ with the development of modern science and technology.

The road back home may be difficult before the Spring Festival, ______ the desire to get together with family members can never be stopped.

We have T-shirts_______red, white, orange and blue______only 25 dollars.[ ]

They poured waste water the river. [ ]

My computer game is_____ the drawer and my books are_____ the sofa. [ ]