You must keep your eyes _________ when you do eye exercises.
— There is growing _____ about house prices.— Don’t worry! Something has been done.
Everyone knows that________ is dangerous to play with fire, but________ is difficult is to prevent children from playing with fire.
One can ______ BBC _____ the air early with his Short-wave radio.
— How many teachers are party members in your school?— Party members_________ one fifth of the number of the teachers in our school.
Jim was born on a farm, _____, he knows little about farming.