【单选题】有关普通X线机管电压预示与补偿,下列说法正确的是
B.
管电压的预示是通过在高压初级电路中串联以电压表预示
C.
由于高压初级电路各元器件电阻的存在,在管电流减小时,高压初级电路会产生较大的电压降
D.
电阻式管电压补偿电路是利用电阻分压,KV表只测量高压初级端电压的一部分
【简答题】Now you will hear an interview about preserving important life stories. Listen carefully and complete the answers to the following questions according to what you hear. u05_1.mp3: 1. What is StoryCorp...
【单选题】Now you will hear a passage. At the end of the passage, you will hear some questions. After you hear a question, choose the best answer from the four choices.
A.
She considers herself very special.
B.
She considers herself the same as others.
C.
She considers herself a confident woman.
D.
She considers herself an experienced doctor.
【单选题】Now you will hear a passage. At the end of the passage, you will hear some questions. After you hear a question, choose the best answer from the four choices.
A.
She lost an arm and a leg.
B.
She began to live a normal life.
C.
She moved to China with her family.
D.
She almost died from a serious disease.
【单选题】Now you will hear a passage. At the end of the passage, you will hear some questions. After you hear a question, choose the best answer from the four choices.
A.
Because she had strong anxiety to help patients.
B.
Because she would not let others see her missing limbs.
C.
Because an admissions officer thought she couldn’t be a doctor.
D.
Because admissions officers refused to give reasons to reject her.
【多选题】关于管路特性阻力,以下说法正确的是()。
A.
串联管路的总特性阻力系数大于任何一段分管段的特性阻力系数
B.
并联管路的总特性阻力系数小于任何一段分管段的特性阻力系数
【单选题】.在信息资源规划中,建立子系统—功能模块—程序模块模型,属于()。
【多选题】关于下列串联型控制器工作方式说法正确的有( )
D.
与并联型控制器的电路结构相似,区别仅仅是将开关器件S1由并联在太阳能电池输出端改为串联在蓄电池充电回路中。