Safety signs and modal verbs

Safety gloves ______________ be worn by electricians.

• must

• can

You ________________be very careful here, because there is risk of fire.

• can

• should

If you supervising or working on a construction site, you _______________ wear a helmet.

• can

• must

"You are not allowed to eat in here" = "You _____________ eat in here"

• mustn't

• shouldn't

"It is highly recommended that you pay attention to the electrical equipment" = You ___________________ pay close attention to the electrical equipment"

• could

• should

Fire assembly point is a place where people ____________ go in case of an emergency evacuation.

• have to

• can

You ____________________ be careful: Fork lift trucks are on operation.

• could

• should

You _______________ speak loudly in a library.

• don't have to

• can't

You ________________ stand clear of suspended load.

• should

• can

You _______________ smoke in this place.

• mustn't

• can