P.德拜(Debye)和E.休克(Hückel)提出的关于强电解质溶液活度计算的理论,包括如下假设()。
A.溶剂水被认为是只提供介电常数(D)的连续介质,完全忽略加入电解质后溶液介电常数的变化以及水分子与离子间的水化作用;
B.溶质完全离解成离子;
C.离子间的相互作用只有库仑力,而其他作用力都忽略不计;
D.离子是带电的硬球,电荷不会被极化,离子电场球形对称。
A.溶剂水被认为是只提供介电常数(D)的连续介质,完全忽略加入电解质后溶液介电常数的变化以及水分子与离子间的水化作用;
B.溶质完全离解成离子;
C.离子间的相互作用只有库仑力,而其他作用力都忽略不计;
D.离子是带电的硬球,电荷不会被极化,离子电场球形对称。
Today the goal of P. E. classes is to______.
A.help all the students exercise
B.create competition among students
C.produce good athletes
D.avoid competitive sports
We can infer from the passage that______.
A.parents all agree with the idea of avoiding competitive sports
B.parents enjoyed their P. E. classes when they were students
C.a lot of attention is paid to students' academic subjects
D.a lot of schools don't have enough P. E. teachers
A.休克早期脉搏细速或摸不清
B.休克患者的体温均偏低
C.尿量≥30ml/h时,表明休克已纠正
D.休克抑制期的患者可有兴奋或烦躁不安的表现
低血钾的治疗措施中,下列哪项是错误的 ()
A. 能口服的患者首先考虑口服补钾
B. 通常是采取分次补钾,边治疗边观察的方法
C. 严重低血钾患者每天补充氯化钾的量可达9g
D. 静脉补充钾时每升输液中含氯化钾量应为3~6g,且应缓慢滴注
E. 休克病人,应先恢复血容量,待尿量超过40ml/h后,再静脉补钾
We travelled on the 6:45 a. m. train to Boston, ______arrived at 8:30 p. m.
A.that
B.which
C.it
D.what
What would you do if you want room service at 24 p. m. ?
A.Phone the Reception desk.
B.Go to the Reception desk.
C.Phone the room staff.
D.Fill out a card ahead.