【单选题】在NH3-NH4Cl缓冲对中,抗酸成分是( )。
【判断题】数控机床的缺点是:与普通机床相比,数控机床价格昂贵,养护与维修费用较高,如果使用和管理不善,容易造成浪费并直接影响用户经济效益。( )
【判断题】与普通机床相比,数控机床价格昂贵,养护与维修费用较高,如果使用和管理不善,容易造成浪费并直接影响经济效益。( )
【单选题】What is Qu Boyu’s advice to Yan He?
A.
Refuse the Duke’s offer and just be a civilian
B.
Obey whatever the young man says and protect himself
C.
Be a strict teacher and don’t be afraid of the danger
D.
Teach him in a wise way that would not anger him
【单选题】在NH3·H2O - NH4Cl缓冲溶液中,抗酸成分是( )。
【单选题】Why does the man live in a flat with two other boys?