Найди валентность иода в его соединении с кислородом, формула соединения — I2O7.

Ответ запиши римской цифрой.

Нужно поставить глагол в нужную форму (глагол в скобках):
1) When I (to come) home my sister already (to return) and (to sit) at the fire  place already a book.
2) It was very late. I (to go) to bed when my father (to return) home.
3) Who (to make) all that noise? I can't haer anything.
4) When you(to see) him last&
5) I (to pepare) my report for 2 weeks but I(not to finish) it yet.
6) You(to be) so heartless. He (to wait) for you for two hours, I think he(to go) away soon.