barirrra,
определите в них видовременные формы глаголов и укажите их инфинитив: тут тож выделить)
1 In prehistoric times people found cereals and tried to cultivate them.
2 calcium is crucial to the growth of bones and teeth
3 This new product will contain many mineral necessary for the body.
4 a small quantity of iodine is also necessary for good nytrition