填空题。 1. In 1846, the United States____ (向……宣战 ) Mexico. 2. They _____ (定居 ;习惯于) new towns. 3. ____ (人们相信)that before long the mix of nationalities will be so great that there will be no distinct major racial or cultural groups. 4. I ____ (一起合作 ) a couple from my hotel and hired a car. 5. He was puzzled by a math problem and then a new idea suddenly___ (使想起) him. |