You ................ use cellphone in class.
can't
You ............... be quiet in class.
must/have to
You must keeps the ocean clean. (Find the mistake)
keeps
................. throw trash into the ocean.
Don't
(choose the incorrect one) You MUST/CAN'T/HAVE TO listen while others are speaking.
CAN'T
CAN'T/DON'T/HAVE TO cheat in exams.
Don't
You CAN'T/DON'T/MUST take photos here.
CAN'T
You ....................... save water.
must/have to
....................... fight with your friends. Be nice!
Don't
You must walk on the grass. (Find the mistake)
must
..................... be late.
Don't
You MUST/CAN'T/MUSTN'T do homework.
MUST
Can't sleep during lessons. (Find the mistake)
Can't
You can't put garbage in the bin. (Find the mistake)
can't
