对钩体病诊断意义较大的常用实验室检查内容是（）
A.血常规和血沉
B.尿常规
C.钩体显微镜下凝集试验
D.血培养
E.PCR检测钩体DNA
参考答案：C
The CPU does not have to look (66) all of RAM to find the spot it needs. But RAM only (67) the data temporarily. As soon as you switch the computer (68) , all that information disappears from the RAM. When you switch the computer on again, the RAM is (69) , and ready (70) a new program and new data.
（68）处填（）。
A．off
B．on
C．up
D．down
由于采用的基期不同，增长速度可分为（）和环比增长速度两种。
