Alot of fish (live или lives) in this lake.

A lot of fish live in this lake,окончание добавлять не нужно,т.к fish у тебя в единственном числе,тоже без окончания.
Переводится предложение как "Много рыбы живет в этом озере"

Vegetable tissues can be formed either by the same cells or by different ones. Like the animal tissues they perform various functions. The rudimentary tissue locates in the places of plants growth and shapes the meristem. The greater part of the total mass of a plant is arranged by the supporting and the nutritive ones. They impart strenght and conserve the nutritives. The pritective tissue covers the leaves, the stem and the roots and serves to defend a plant against injury. The roots, the stem and the leaves are penetrated by a lot of vessels providing the transportation of sap all over the plant. It is the function of the conductive tissue.

My mother bougth tickets at the box office last week. She invited me to the theatre, I felt excited to see a ballet.
On sunday we arrived at the theatre and left our clothes at the cloakroom. 
After that we went to have our seats in a box, there were not expensive tickets, then we bought a programme, my mother had opera glasses.
The lights went down and the ballet began. During the interval we walked to the orchestra-pit. And we went to the buffet to eat tasty cakes.
When the performance was over the curtains fell and all people were applauding loudly. We engoyed ourselves by watching the ballet.