1.

1) It's cold today, isn't it?

2) Nobody has arrived yet, have they?

3) I'm not late, am I?

4) He will come to work, won't he?

5) It won't be difficult, will it?

2.

1) They shouldn't smoke, should they?

2) Kate and Mary can't swim, can they?

3) John must stay, mustn't he?

4) You should apologize for what you have done, shouldn't you?

5) She can't speak Arabic, can she?

1.1 isn't it

1.2 have they

1.3 am I

1.4 won't he

1.5 have you

1.6 will it

2.1 should they

2.2 can they

2.3 mustn't he

2.4 shouldn't you

2.5 can she