Ex4 Insert prepositions:
1. Algebra is widely used geometry ___ the metric relations.

2. Algebraic methods ___ the solution ___ geometric problems are very important .
3.Trigonometry is a branch mathematics which deals the relations ___ the angled and

sides triangles.
4. This equation is taken ___ the well-known treatise ___- euclid .

5. He succeeded solving this problem .​

Dear Christina/Valerie!You I was once advised to visit Mars,that I write to you from this great planet .Thanks for the stones of Saturn.I thought they were solid,and they're like marmalade. I shared them with new friends from Mars.They're all so bright .I showed them the cartoon "My little pony". All the Martians appreciated .We staged the first Martian fair,we ordered the Express delivery of stones,I was told that they are hallucinogenic .We got three ponies ,threw apricot silver ,black tomatoes told us about the Korean women,and that they like the work of Stephen king,which surprised me .I told them about how we have fun when we go out ,and told me when I rode a motorcycle ,right here I've explained what a motorcycle is ,but explained .Because of this, they decided to screw me on a flying saucer.In the end I liked it.We tried to avoid outer geese with blue eyes,but they disliked me ,and there was a sheep he was defending geese.Like a farm.

St Petersburg is a famous Russian city situated on the Neva River.  In 1914 the city got the name of Petrograd and changed it
for Leningrad in 1924. It became St Petersburg again in 1991. Peter the Great founded the city in 1703 and moved the capital from Moscow to St Petersburg in 1712. beautiful Winter Palace appeared in Dvortsovaya (Palace) Square with a tall column in its centre. the famous monument to Peter the Great on the bank of the Neva River. St Petersburg is famous for its palaces and bridges: its churches, theatres and museums, its wonderful parks and gardens, The Summer Garden. Every year a lot of tourists come to see this beautiful city.