Thank you for your last letter. I'm so glad because you can come to my city to______.I______we will have a good time together. But do you know______to get to my home? Let me_____you now. You can______a plane to my city because your city is very far from my city. After you get out of the airport, you can take a taxi,go straight along Bridge Street, and then you can see a ______on your left. Cross the bridge and then______right at the science museum. Go along Dongfang Street and my______is on your left. It's______the post office and the supermarket. You won't miss it! There are many______places in my city, and I can take you there. I'm looking forward to your coming.

I ______ a bad cough and a high fever. So I didn’t go to school ______morning. After breakfast, I______a storybook. There’re many signs ______it. From this book I know ______ about traffic（交通）.We should walk or drive on the ______ of the road（路）and get slower（慢下来）at the cross of the road. “Red light” means ______. “Green light” means ______. We ______ go in the time of “Red light”. We must ______ the “Green light” and go.

Some scientists were working in a spaceship in outer space. They looked out of the ________ of the spaceship. They could ________ the planet Earth. It looked like a blue and white ______. Scientists ________ very powerful cameras. They took many ________ of our planet from outer space. The photos were very ________. The scientists were surprised at ________ they saw.

In the photos, they saw land, blue sea and ________ clouds. Some scientists said they could see a ________, dark line on the yellow earth. They thought it ________ the Great Wall of China! Do you think so?

Every day some people are killed（被杀）while they are crossing the roads. ______ of these people are old people and children. Old people are often killed because they can't see or ______ very well. Children are killed because they are not ______. They forget to look and listen before they ______ the roads. A car or a bus can’t stop ______. If a car is going very fast, it will travel many metres ______ it stops. Some people don't always understand this. They think a car can stop ______ a few metres. It is difficult to ______ how fast a car is moving. The only way to cross the roads safely is to look ______sides, right and left. Then if the roads are ______, you can cross them.