题目

Dogs are known for a strong sense of smell. Their noses can be trained to identify different smells. Dogs are often used in search and rescue operations and to sniff for things like drugs and explosives. Some dogs have even been trained to sniff for cancer in people. Researchers have been trying to reproduce the extraordinary sense of smell that real dogs are born with. Now, officials at the Glasgow airport in Scotland are testing a new security device called an “electronic sniffer dog”. The electronic sniffer dog represents one of the latest developments in the area of smell technol脱式计算（用自己喜欢的方法计算）． 102×4.5= 4.5×7.3+2.7×4.5 0.85×0.4×2.5 8×（20-1.25） 125×0.32×25 （15.6+1.32÷0.3）×0.5．