Read the following passage and mark the letter A, B, C or D to indicate the correct word or phrase that best fits each of the numbered blanks.

There have been concerns about health problem in the area recently as the last reported to cause the pollution. To stay from worries, we decided (23)     ______a health check with the local doctor. We phoned to make an (24)________at 9 o'clock the next morning, the doctor welcomed us (25)_____ the door with a lovely smile. After (26) ___ necessary forms, we were given different tests. All the tests were done very quickly with the net of modern (27)_____ . As she did the checks, the doctor said that a lot of people were worried about air pollution and came to help for health checks like us.