用科学记数法表示0.00009=______．
0.00009=9×10-5；
故答案为：9×10-5．
火箭免疫电泳终点应（）
A.火箭峰呈云雾状
B.火箭峰呈圆形
C.火箭峰顶部与基底同宽
D.火箭峰尖而清晰
E.火箭峰呈纺锤状
Sixty percent of all Chinese are farmers and they are than people who live in the cities.
A. poor B. much poorer C. much richer
