当神经受损时，最先发生改变的是（）
A.细胞核
B.神经元纤维
C.尼氏小体
D.细胞浆
E.细胞膜
参考答案：C
----I am sorry to tell you that I can’t arrive on time as planned due to the delay of the flight. You have to look after your brother yourself tomorrow.
----Don’t worry, uncle. There’s .
A．no exception
B．no wonder
C．no doubt
D．no hurry
人的体细胞、红细胞、血小板、生殖细胞、白细胞内分别有多少个DNA分子：
A．46 23 16 23 46
B．46 0 46 23 23
C．46 0 0 23 46
D．46 0 23 23 23
