第4题: [单项选择]The boom indicator tells the operator at what angle the boom is compared to the(). A. horizontal position of the boom B. vertical position of the boom C. horizontal position of the load being lifted D. vertical position of the load being lifted 参考答案:A
第5题: [单项选择]牙体切割最表浅的修复体是 A. 半冠 B. 嵌体 C. 锤造全冠 D. 铸造金属全冠 E. 3/4冠 参考答案:C