The air in Dongying is much worse than that in many other cities. We must do to protect our environment.

Since no evidence has been found so far he was guilty, he has to be set free.

1 is a good idea to bring your camerabecause you may want to take photos of the autumn leaves.

had to report the accident _______ length as the reporter asked me to describe it _______ detail.

Had the governments and scientists not worked together, AIDS-related deaths _______ since their highest in 2005.