分度号为Cu50热电阻在0℃时的电阻值为（）。
A.0Ω
B.53Ω
C.50Ω
D.100Ω
参考答案：C
二、名词解释
行动研究________________________________________
In an effort to plan out expenses, the Roberts family is representing its annual budget as a circle graph. Each sector of the graph is proportional to the amount of the budget it represents. If "clothes and shoes" takes up 54° of the chart, how much of the Roberts’s $20,000 annual budget is dedicated to clothes and shoes ？（）
A. $1,500
B. $3,000
C. $4,500
D. $5,000
E. $5,400
