【单选题】Which medium is commonly used for the detection of bacterial motility and transportation of bacteria?
【判断题】“海内存知己,天涯若比邻。”选自《赠汪伦》。( )
【单选题】Which of the following can be categorized into the group of medium priority?
A.
Which of the following can be categorized into the group of medium priority?
B.
Writing a paper on the problem of air pollution that is due tomorrow.
C.
Preparing for a job interview that is there weeks away
D.
Preparing for a mid-term that is only three days away.
【单选题】在铣端面齿槽时,说法正确的选项是()
A.
当工件前角γ≠0°时,转动分度手柄,使工作铣刀端面刃对准圆周齿前面即可进行铣削
B.
当工件前角γ=0°时,工作台应向铣刀锥面一方偏移D/2后,再转动分度手柄铣削
C.
当工件前角γ>0°时,在单角铣刀端面切削刃对准工件中心后,还需将工作台向铣刀锥面方向移动一个偏移量,再转动分度手柄,使工件前刀面与铣刀端面切削刃对准进行试铣
D.
当工件前角γ>0°时,工作台应向铣刀锥面反方向移动D/2sinγ后,再转动分度手柄铣削
【单选题】Which of the following statements is NOT true of the cosmos?
A.
Microwaves are the medium WMAP used to make measurements.
B.
Warmer spots would finally develop into the clusters of galaxies.
C.
Dark energy is a decisive factor in the cosmic expansion.
D.
The nature of dark matter in space is unknown to scientists.