第7题: [单项选择]超声探头的核心是压电晶片,其作用是( ) A. 能将电能转换为机械能,亦能将机械能转换为电能 B. 能将电能转换为机械能,但不能将机械能转换为电能 C. 不能将电能转换为机械能,但能将机械能转换为电能 D. 不能将电能转换为机械能,亦不能将机械能转换为电能 E. 以上都不对 参考答案:A
第13题: [单项选择]The most important customer a technician has is:() A. the customer standing right in front of them. B. the customer who owes the company the most money. C. the customer calling on the phone. D. the customer they have an appointment with in an hour. 参考答案:A