We have to pay a ____ to enter that bridge.
commuter / rush hour / toll
There are not much vehicles during the ________.
rush hour / off-peak hour / rush peak hour
USA in a ______ country, while Cambodia is a _______ country.
developing, developed / developed, developing
Do not drive on that road. There is a heavy traffic _______.
commuter / congestion / developed
The _____ in this city is too much! Cover your nose!
congestion / smog / toll