Раскройте скобки употребляя глаголы в past simple или past perfect 1.when i (to come) home, mother already (to cook) dinner. 2.when the teacher (to enter )the classroom, the pupils already (to open) their books. 3.kate (to give) me the book which she (to buy) the day before. 4.nick (to show) the teacher the picture which he (to draw). 5.the teacher (to understand) that lena (not to do) her home work.

1. when i came home, mother had already cooked dinner.2. when the teacher entered the classroom, the pupils had already opened their books.3. kate gave me the book which she had bought the day before.  4. nick showed the teacher the picture which he had drawn.5.the teacher understood that lena hadn't done her home work.

1. i must brush my teeth. - anyone, most likely some disobedient child.

2. i have to brush my teeth. - a patient of dentist's, a human with diseased tooth.

3. i must tidy my room. - anyone, most likely some disobedient child.

4.i have to tidy my room. - anyone, probably a child.

5. i must take the medicine. - someone with easy form of illness.

6. i have to take the medicine. - most likely, a regular patient

a - have been

b - have not had. saw 

a - was

b - left. came. have found/