神经细胞处于静息状态时
A．仅有少量K+外流B．仅有少量Na+内流C．没有K+和Na+的净扩散D．有少量K+外流和Na+内流
参考答案：D
- Did Jack come back early last night?
- Yes. It was not yet eight o'clock ______ he got home. [ ]
A. before
B. when
C. that
D. until
下列化学用语书写正确的是
A．一氧化碳：Co
B．铜离子：Cu+2
C．氢氧化镁：Mg(OH)2
D．氧化铝：AlO
