第16题: [单项选择]Why did Dr. Smith come to settle down in a village in the Himalayas A. It is in the plains. B. It is cooler there. C. The villagers convinced him to stay. D. There isn’t much poverty. 参考答案:B
第21题: [单项选择]有一段阶梯,如果每步跨4级,最后会剩下2级,如果每步跨5级,最后则会剩下1级。已知这段阶梯的级数可以被3整除,则这段阶梯共有( )级。 A. 42 B. 46 C. 63 D. 66 参考答案:D 答案解析:[解析] 设阶梯共有x级,X除以4余2,除以5余1,根据同余问题“和同加和”的规律,X可以表示为20N+6,B、D均符合。又因为阶梯的级数可以被3整除,所以排除B项,本题正确答案为D。