Пожалуйста решите задачу. В прямоугольнике ABCD сторона CD=18 см, диагональ AC образует со стороной CD угол 30 градусов. Найти расстояние от вершины В до диагонали AC.

В лейку налили 3л вода, в ведро-в 4 раза больше, чем в лейку, а в бочку-на 28л больше, чем в ведро. Сколько всего литров воды налили в лейку, ведро и бочку? ( Реши задачу по действиям с пояснениями).

Упр. 211. Раскройте скобки, употребляя глаголы в Present Perfect, Present Simple, Present Continuous, Past Simple или Past Continuous.

1. They (to go) to the Hermitage last week. 2. They (to be) to the Hermitage twice this week. 3. After school yesterday he (to come) home, (to have) dinner, (to read) an article from the latest magazine and (to begin) doing his homework. 4. When your friend (to return) from the south? — She (to return) yesterday. — You (to go) to the station to meet her? — No, I..., I (to be) too busy. 5. With whom you (to discuss) this question yesterday? 6. I (to see) this film this week. I like it very much. 7. When I (to enter) the kitchen, I (to see) that my mother (to stand) at the table and (to cut) some cabbage. She (to cook) dinner. 8. As soon as I (to hear) a cry, I (to run) out of the room and (to see) that a child (to lie) on the ground and (to cry). "What (to happen)? Why you (to cry)?

происхождение восточных словян

Осуществите цепочку превращения медь-оксид азота(IV)-азотная кислота-нитрат алюминия-оксид алюминия-сульфат алюминия.