【判断题】事故井井口失控后就无法实现救援井与事故井的连通。
【单选题】A pump is defined as device that
B.
imparts energy to a fluid to move it from level ‘A’ to level ‘B’
C.
creates a vacuum to move a liquid in all installation
D.
is to develop a pressure differential
【单选题】关于队员未经裁判员允许擅自离场的说法中,以下哪种说法是正确的?
A.
运动员绝不可以在未经裁判员允许的情况下擅自离场。
【单选题】A market is defined as
A.
a physical place where people buy only goods.
B.
a physical place where people buy both goods and services.
C.
a store where people buy physical goods.
D.
any arrangement that brings buyers and sellers together.
E.
a place where one good is bartered for another.
【判断题】A nanoparticle is defined a nano-object with one external dimensions in the nanoscale.
【判断题】If A2 is defined then A is necessarily square.