1. Did your teacher mention taking...
2. The principal promises that safety measures are being applied immediately to vocational courses.
3. Gagarin flew into space eight years before Armstrong walked on the moon.
4. It is useful for us to know about how our people used to live in the past.
5. Ha Long Bay has been recognized by UNESCO as a World Heritage Site.
6. Many ethnic people in mountainous areas are illiterate.
7. There were over one hundred participants at the forum.
8. You can spend your time sightseeing, shopping, or you can simply relax on one of the excellent beaches.
Part 4:
1. To make this soup, you need two stalks of celery. (celery, not slices)
2. He always feels left out when his friends talk about sports. (left off should be left out)
3. Even though Mercury is the closest planet to the sun, it is not actually the hottest. (hotter, not hotter)
4. A bicycle is among the most efficient machines invented by man. (Bicycle should be capitalized)
Part 5:
1. They reported that two people had been injured in the accident.
=> It was reported that two people had been injured in the accident.
2. "We will visit you this week," my parents told me.
=> My parents told me that they would visit me that week.
3. I think you should spend more time improving your pronunciation.
=> If I were you, I'd spend more time improving my pronunciation.
4. The new girl in our class is reasonably good at English. Her name is Mi.
=> The new girl in our class, Mi, is reasonably good at English.