Раскройте скобки,пожалуйста .
1)Look!He(to swim)across the river
2)My friend(to ride)a bike soon
3)Russia (to be)a very big country
4)She(not to speak)English yesterday
5)Mike(not to see)his friends last year
6)Her friends (to bake)a cake now
7)Mike(not to waatch)TV 2 weeks ago
8)My teacher(to read)a lot of texts yesterday
9)Listen!She(to sing) a song
10) My mother(to have)dinner now

ПОМОГИТЕ .Я тему не понял .