The correnct description about the process of repolarization phase of AP is A: only be attributed to the Na+ channel inactivation. B: only be attributed to the activation of K+ channel. C: attributed to both the Na+ inactivation and K+ channel activation. D: only be attributed to the Cl- channel activatio.

顿挫感染（）。 A: B: BiosynthEsis C: D: ABortivEinfECtion E: F: DEfECtivEvirus G: H: inACtivAtion I: J: suhvins

Orphan families are families of genes that: A: Lack homologs in other species. B: Have no known function. C: Have no phenotypic change after gene inactivation. D: Have not yet been studied.

基因治疗的策略包括（） A: 基因置换（gene replacement） B: 基因修正（gene correction） C: 基因转移（gene augmentation） D: 基因灭活（gene inactivation

Inactivation of acetyl CoA carboxylase is favored WHEN: A: Cytosolic citrate levels are high. B: It is in a polymeric form. C: Palmitoyl CoA levels are low. D: The tricarboxylate transporter is inhibited. E: It is dephosphorylated.

下列关于X染色体失活的描述正确的是（ ）‍ A: X染色体失活发生在雄性个体 B: 随机失活的那条X染色体所有的基因都不转录 C: 只有在即将失活的X染色体上，X inactivation center (XIC)才会转录出非编码RNA (noncoding RNA) Xist D: 非编码RNA Xist结合在非自身转录来源的X染色体上