C. Listen to the short passage, and fill in the blanks with the words you hear. The passage will be read twice. Even though he has cleaned skyscrapers for about 20 years, Hu Bensheng, 39, still feels 1) _______ every time he scales the heights. The job is much more difficult than people might imagine, he says. "In good conditions it usually takes us 20 working days to complete a 2) _______ building. But with the time off for wind or rain added, that can stretch to a month.” "I have been in this 3) _______for 20 years and have not seen an accident in our company. We attach great importance to 4) _______. Both the work ropes and safety ropes have to be changed every two years under government 5)_______, but our company changes them more frequently to be on the safe side."