Complete the task

Choose the correct word

1 Lynn has [already|since] left for Thailand.

2 I haven't spoken to Ben [since|for] last summer.

3 They haven't finished building the new school [yet|since].

4 Paul has [never|for] volunteered for a charity.

5 Tim has [just|yet] published his third novel.

6 Martin has known her [for|since] two years.