微需氧菌生长最好的氧的含量为（）
A.2%～3%
B.3%～5%
C.5%～6%
D.6%～8%
E.8%～10%
F.以上均不对
参考答案：C
Windows 98的安装方式包括______、DOS安装和新安装。
The most common symptom associated with bladder cancer is()
A. burning on urination.
B. frequent infections.
C. painless hematuria.
D. decreasing urine output.
