对于工作循环周期较长的复杂脑力劳动，适用的工作分析方法是（）。
A.观察法
B.工作实践法
C.访谈法
D.因素比较法
参考答案：C
采用工程量清单计价法进行招标时，招标控制价应在招标文件中公布。（）
It can be inferred from the passage that ______
A．vanillin is easier to synthesize than benzaldehyde
B．not all synthetic flavors are harmless
C．in general, the less components there are in a fragrance, the harder it is to synthesize
D．synthesized substances must be tested for safety only if they are used in food
