气温过低，空气湿度过大，将影响油漆漆膜的附着力，所以不允许进行涂装作业。
参考答案：对
成本类科目包括制造费用、生产成本及主营业务成本等科目。（）
An analyst does research about investment risk. Which of the following statements best describes systematic risk（）
A. Total risk.
B. Diversifiable risk.
C. Variability in all risky assets caused by macroeconomic variability.
