The number of tigers in Asia ________ getting smaller and smaller and a large number of

people _________ trying to protect them. [ ]

A. are; are

B. is; is

C. is; are

D. are; is

有关钾的代谢的叙述正确的是

A．钾离子在细胞外液中浓度最高
B．血钾过高可使心肌过度兴奋
C．缺钾时应静脉注射0.3%氯化钾
D．低血钾时，补钾速度一般成人为60滴/分
E．糖原合成时，钾由细胞内向细胞外转移