【简答题】声音在真空中不能传播,光在真空中的速度为______m/s,通常认为声音在空气中的速度为______m/s.
【简答题】Technician A says that pistons are usually made of an aluminum alloy. Technician B says that pistons are usually made of stainless steel. Who is correct?A. Technician A. B. Technician B. C. Both Techn...
【简答题】电视信号通过电磁波传输,其传输速度与真空中光速相同,为 m/s。
【单选题】真空中光速为3×108 m/s,波长为380 nm的紫光,其频率为()。
【单选题】The technician took one day to complete the task which I planned to fulfill within a week.
A.
这位技术员花一天时间完成任务,而我却要用一周来完成。
B.
这位技术员花一周时间完成任务,而我只要一天的时间。
C.
这位技术员花一天时间完成了我原计划用一周完成的任务。
【简答题】Technician A says that airflow can be measured directly. Technician B says that airflow can be calculated. Who is correct?A. Technician A. B. Technician B. C. Both Technician A and Technician B. D. Ne...
【单选题】Technician A says that the diodes regulate the generator output voltage. Technician B says that the field current can be computer controlled. Which technician is correct? _____
C.
Both Technicians A and B
D.
Neither Technician A nor B
【单选题】真空中光速为3×10 8 m/s,一个透明介质的折射率为2.0,光在该介质中的速度为( )
【单选题】Technician A says that DOT 5 brake fluid can be added to DOT 3 brake fluid. Technician B says that it is wise to purchase brake fluid that is in metal rather than plastic containers. Which technician ...
C.
Both technician A and B
D.
Neither technician A nor B