1. Our English teacher often says we ______ remember enough English words.
 A. mustn’t    B. shouldn’t   C. cannot   D. needn’t
2. In recent years ______global warming is becoming ______concern of people all over the world.
 A. the, the      B. /, /    C. /, a      D. the, /
3. Mr. White, who comes from ______European country, has formed ______ habit of attending _____ church on Sundays.
 A. an, /, the     B. a, the, /     C. an, the, /     D. a, a, a