Read the text again and write True or False for sentence 1-8. Correct the false sentences.
1 A force can make things move.
Gravity gets weaker when an object has more mass..
3. We feel weight because something is under our feet.
4 We are falling when we are in orbit around the Earth
5 We measure mass in Newtons.
6 If you increase the mass of an object, it will weigh more.
7 An object's mass changes depending on the planet.
8 An elephant weighs more on Earth than it does on the Moon. ​

The USA is situated in the central part of North America and it is washed by the Pacific Ocean, the Atlantic Ocean and the Gulf of Mexico (Present Simple)

There are two main political parties in the USA: the Democratic (symbolized by a “donkey”) and the Republican (its symbol is an “elephant”) (Present Simple)

The flag of the USA is called “Stars and Stripes” (Present Simple)

Such industries as machine-building, ship-building are highly developed in the country (Present Simple)

Везде Present Simple, т.к. ведётся повествование.

1. You had a long day, you must be tired.
2. You should eat more fruits and vegetables. It's good for your health.
3. You should read this book. It's very interesting.
4. How can I help you?
5. He has a big family, he has to work every day.
6. The conference must begin on Monday.
7. I couldn't call him yesterday, I was very busy.
8. Can I call you tomorrow afternoon?
9. This is a very interesting movie. You should see it.
10. I have to get up early since I live far away from work.

He went on business trip last month или in the last month (оба варианта допустимы)