1. It’s recommended that we become more concerned ___________the environment around us.
A. of B. to C. about D. with
2. Air ____________ together with littering, is causing many problems in our cities today.
A. pollute B. polluted C. polluting D. pollution
3. In the United States, there are 50____________ and six different time zones across the country.
A. states B. nations C. towns D. countries
4. When a typhoon happened, many houses and roads ____________ destroyed or flooded.
A. is B. are C. were D. was
5. ____________ is the most common natural disaster in your country?
A. What B. Which C. How D. Who
6. ____________ you ever been to any EnglishSpeaking countries?
A. Do B. Are C. Were D. Have
7. If you ____________ yourself well, your parents will be happy.
A. behaves B. behaved C. behave D. behaving
8. He regretted not ______saying______ goodbye to his girlfriend at the airport.
A. to say B. say C. said D. to saying
9. If I ____________ you, I would see the doctor immediately.
A. am B. were C. was D. will be
10. The teacher said ____________ a week off on the occasion of the International Labor Day.
A. we will have B. we did have C. we have D. we would have