Directions:There are 10 questions in this part of the
test. Read the passage through. Then, go back and choose one suitable word or
phrase marked A, B, C, or D for each blank in the passage. Mark the
corresponding letter of the word or phrase you have chosen with a single bar
across the square brackets on your machine-scored Answer Sheet. The word "smog" has become a household word in urban China. Smog
is an 1 of greenhouse gases and
pollutants that reduce visibility and harm respiratory functions. Smog is
typically 2 cities with high
concentrations of cars and factories. The population density, amount of industry
and the fuels used 3 together to have
an impact on smog levels. During summer, smog is worse
4 the production of ozone, the main component of smog,
increases in strong sunlight. The important thing to understand about smog is
that this kind of pollution is spread out 5 large distances. Walking, biking or using public
transportation can help limit ozone production. 6
, decreasing household electricity use and keeping your vehicles
fuel-efficient reduces 7 greenhouse
gases. Checking tire pressure, oil levels, air filters, and getting regular
maintenance help 8 fuel efficiency. Be
sure to use only the fuel recommended in the vehicle’s user
9 . Simple steps like avoiding stop-and-go traffic and
reducing vehicle workload decrease smog-related emissions. To lighten the
workload, avoid running the air-conditioner, 10
the engine and carrying heavy objects in the vehicle.