Past simple or present perfect 1. your relatives (take part) in the demonstration yesterday.
2. Your parents (tell) you about the project today.

1. took part

2. have told

1) say2)said3)telling4)said5) tell6)says7)tell8)tell9)10)tell крайней мере исходила из правил,даже грамматику сейчас перечитала))

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