Choose the right variant 1. i dont know these words. i them/ a. must b.have to c. dont have to 2. listen to their teacher. a. have to b.havent to c. must 3.i do my homework because i have already done it. a. mustnt b. dont have to c.must .

1. I dont know these words. I must learn them.
Я не знаю эти слова. Я должен изучать их.
2. Pupils must listen to their teacher.
Ученики должны слушать своего учителя. 
3. I mustnt do my homework because I have already done it.
Я не должен делать мою домашнюю работу, потому что я уже сделал ее.