第20题: [单项选择]承担大部分咀嚼压力的是 A. 嵌体 B. 半冠 C. 烤瓷熔附金属全冠 D. 桩冠 E. 3/4冠 参考答案:A
第21题: [单项选择]Australia is a nation of immigrants because the overwhelming majority of the Australian population are(). A. white B. middle class people C. tourists from other countries D. immigrants or their descendants 参考答案:D