Many of the students take their c_________ into the classroom to help them do some maths work, which is not preferred by the teachers.

Once he was considered to be s__________, for he couldn’t work out the simplest numbers.

 Robots can also be called a________ i____________.

A good c_______ when facing difficulties is to stay calm.

It's dangerous for a young lady w________ in the street late at night.

Would you please find a m_______ to sweep the floor? It’s too dirty.