в равнобедренном треугольнике основание равно 47√3 , а угол, лежащий напротив основания равен 120⁰ ( градусов) . надите площадь треугольника

Какой обьем воды надо добавить к 12,4 г оксида натрия, чтобы получить 10% раствор?

Underline the correct item.

1) By the time Graham arrived at the train station, the train has already been leaving/had already left.

2) How long had you been trying/had you tried to call Tom before he finally answered the phone.

3) The children had been  putting away/had put away their toys before their mum came back home.

4) Alan had a headache because he had played/had been playing computer games all afternoon.

5) Simon had saved/had been saving money for  many years before he bought his own house.

6) The football game had just been starting/had just started when it began to rain.