当介质一定时，管径增大摩阻损失（）。A、增大 B、减小 C、不_爱下问搜题

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问题单项选择题

当介质一定时，管径增大摩阻损失（）。

A、增大

B、减小

C、不变

D、不定

答案

参考答案：B

单项选择题

伤寒常用的确诊依据是（）

A.血培养和骨髓培养

B.粪培养

C.尿培养

D.肥达反应

E.胆汁培养

完形填空

Eye See You
Vision is the art of seeing what is invisible to others. -- Jonathan Swift
I walked into a wild third-grade classroom. Music was playing _36_, children were under tables applying make-up, kids were throwing a football indoors, and students were _37_ wherever they could find _38_. I was a mid-year _39_. The previous _40_ said he could no longer manage these children and _41_ without notice during the holiday break.
As soon as I walked in the room, I realized why he _42_. I sat down _43_ in my chair and began reading their _44_ softly. After each name, I _45_, asking God to help me understand that child. I then nailed a _46_ to the wall next to the chalkboard and began _47_ my name and a reading assignment on the board. I then asked each child to come to me, and tell me their names and what they wanted to learn. It was a _48_ task, because only two children there wanted to learn something! Rules were _49_, boundaries established, parents contacted. But the mirror saved the day -- no, the year! Unbeknownst(不知的) to the children, the mirror allowed me to see their every _50_ while I was writing on the board. They soon became _51_ as to how I knew who was misbehaving while I was writing on the board. When one student finally asked me, I told him I had a special teacher’s eye in the back of my head that my hair _52_. At first they did not believe me. _53_ they did begin to exhibit better behavior, especially while I wrote on the board, thinking I had magical _54_. I never told them differently. Why _55_ a good thing?

A．representative

B．replacement

D．disappeared

C．indifferently