In the old days, London was a city with dirty air. Today the air in London is better and clean. The sky is clear on a sunny day! There are many old buildings in London. Today new buildings are side by side with the old buildings. Together they make London a beautiful city. Look at the Thames River. The lights are bright at night. In the old day, there were lots of small boats on the river. Now you see big ships. London Bridge is famous all over the world. Can tall ships under this bridge? Yes, the bridge can open for big ships. It’s amazing.
1.The air is in London usually clean now. (______)