Plastic bottles ________ to hold flowers.(can/ design
can be designed
Big companies ______________ to protect the environment. (must / tell)
must be told
Electricity ________ to give power to cars. (can / use)
can be used
The environment ___________ by reducing pollution. (may / save)
may be saved
Lights ________________ off when not in use.(should / turn)
should be turned
Energy-efficient bulbs ____________ at home.(should / use)
should be used
Trash ______________ in the trash can. (should / throw)
should be thrown
Homework _________ before the next class. (must/finish)
must be finished
Class photos _________ on the school website. (might/post)
might be posted
Sports equipment ______ after PE class. (should/return)
should be returned
Birthday cards ______ by classmates during lunch break. (can/give)
can be given
Messages ______ by bees through dance. (can/send)
can be sent
