When you do the test, you have to (29) _________ really hard into a machine, which will then tell you if you are over the limit to drive a vehicle.

Read the following passage and write the letter A, B, C or D on your answer sheet to indicate the correct word or phrase that best fits each of the numbered blanks from 28 to 32.

When you do the test, you have to (29) _________ really hard into a machine, which will then tell you if you are over the limit to drive a vehicle.