Луч света переходит из воздуха в воду.угол его падения равет 60 градусов .найдите угол преломления .показатель преломления воды равет 1.333...

правильно употребить в скобках глаголов в Past Simple, Past Countiuos, Past Perfect 

1. When Alison (to enter) the house she (to see) that her son (to play) with a ball which  she (to buy) in the shop. 

2. They (to arrive) to the thatre. 

3. When I (to come) into her room, she (to play) the piano which her father (ot buy) 

4. He(to want )to impress her parents as he (not to meet) them before. 

5. Mother (to tell) that she (to  plan) fish soup and a chocolate mousse for dinner. 

6. When we (to arrive), mothar (to go) into the kitchen to do the last preparations for the meal.

7. We( to want) to know which way they (to choose). 

Расскажи что изучает фонетика?лексика?Фразеологизмы?словообразование? марфология?

Векторы AB и CD равны.

A(-2,5), B(0.3), D(7.4)

Найти C(x,y)