1. Chess is played for around two thousand years

2. I tried to call you many times last night, but no one answered.

3. Unless he got up early yesterday, he would miss the first bus.

4. There have been major new developments in space research and satellite technology.

5. Fortunately, the river flowing through our town is polluting

6. Thomas Edison was one of the greatest inventors of the world

7. Nam said that he came there the next day

8. He wanted to be a pilot

9. Production of these chemicals causes serious environmental pollution

                                  *** Có sai sót nào mong bạn thông cảm a***

                                                   #chúc bạn học tốt!

                                                                     ^.^