Сделайте нужно) нужно с каждым словом или сделайте нужно) нужно с каждым словом или словосочетанием составить предложение) to do sums; to solve; retell; to do exersices; to prepare a report; to learn by heart.

1) When we study mathematics we always do sums. 
2) Protectoin of enviroment global problem all over the worl, so we should solve it!
3) Our hometask was to retell story in Work Book
4) I like to do exersices every morning
5) Journalist must prepare a report to news. 
6) Today we must learn by heart part of novel by Pushkin