在招标采购服务工作所发生的费用中，( )费用的比例较大。
A．人力资源费 B．市场调研费C．税金 D．专家评审费
参考答案：A
Some of my friends are interested in science,but none of them can tell_____.
A．when UFOs will appear next time.
B．why do horses know the way.
C．where was this kind of plant found.
D．how do elephants communicate.
如何消除邻菲罗啉分光光度法测定水中铁时金属离子的干扰？
