Past perfect or present perfect?
1when the three bears came home they saw that someone (eat) baby bear's porridge. 2jonh is hungry because he (have) nothing to eat since morning.3 he just (see) his friend arrive. 4 it (stop) raining and the sun is shining. 5 she said they(walk)3 miles. 6 they just (walk) in the park.

We always hear many students complain about having to study math or chemistry, even when they don't want to become a doctor or an engeneer. And it's possible to understand, it is actually true, the majority of the students won't even use math in the future. however, it is still important to study compulsory subjects. First of all, there are thousands of jobs that require knowing mathematics, even the final exam mark will matter to a college or the university you'll apply to. Actually, everyone uses math whether they realize it or not. In our everyday life we count in stores to find out how much something costs, and in the future things like that will stay important as well. Math helps us with other subjects, like physics and chemistry. A lot of math problems help the students to solve tasks in physics. 

1. Do you have any garden tools?
2. Dishwasher is very useful invention.
3. Where does this road go?
4. Where was the first time produced a nuclear weapon - in the Europe or in the USA?
5. Sue decided to improve her marks in literature.
6. Diana has eventful life. (Diana leads...)
7. Sergey - an engineer. He has many practical and technical skills.
8. I don't know anything about this culture. The one thing I know, is that they try to grow it on the north.
9. Useless to grow flowers on that ground. It is very bad.
10. The trade helps to improve contacts between countries.