В реакции натрия с водой получится гидроксид натрия с выделением водорода в воздух: Аналогичная ситуация: гидроксид магния: При реакции цинка и сульфида меди получится сульфид цинка и чистая медь: Честно сказать, сомневаюсь насчет данной реакции, возможна ли она вообще, однако, судя по всему, при реакции железа и нитрата свинца получится нитрат железа и свинец в чистом виде: Реакция с хлором вполне: Но вот последнее меня немного шокирует. AgNO3 даже с иодидом натрия это шутка. Думаю, имелась ввиду реакция с хлоридом натрия:
2. He did not eat yesterday.
3. Did you play the piano yesterday?
4. Have you play the piano today?
5. What have you prepared for today?
6. Look at this birdhouse. Mike has made it himself. He made it last Sunday.
7. Where have you put my pen? I cannot find it.
8. Have you seen Mary today?
9. When did you see Mary? — I saw her last week.
10. Did your mother promise to take you to the theatre?
11. Look at my new dress! I have made it myself.
12. He is not at school today, he fell ill. — When did he fall ill? — He fell ill yesterday.
13. I have already done my homework. Now I can go for a walk.
14. I did my homework yesterday.
15. He has just come home.
16. He has come home a minute ago.
17.Nick played football yesterday.
18. She has already come from school. Now she is doing her homework.
19. I read this book last year.
20. I have read this book this year.
21. I have never been to Washington.
22. Have you ever been to New York?
23. Have you ever seen the eruption of a volcano?
24. I invited Linda to the party. — When did you see her? – I have not seen her for ages.
I called her an hour ago.