【单选题】Suppose that the demand curve for desktop computers shifts rightward and at the same time the supply curve shifts leftward. Which of the following could have caused these shifts?
A.
Desktop computers are a normal good and incomes increased, while more firms entered the market.
B.
The price of a laptop computer, a substitute for desktop computers, fell and the cost of producing desktop computers decreased.
C.
Consumers purchased more computers because of the Christmas season and the labor costs of producing desktop computers decreased.
D.
Desktop computers are a normal good and incomes increased, while the labor costs of producing personal computers increased.
E.
Desktop computers are a normal good and incomes decreased, while the labor costs of producing personal computers increased.
【单选题】岩石是一种或多种矿物或岩屑组成的集合体,按其成因分成()三大类。
【单选题】2001年教育部颁布的《基础教育课程改革纲要(试行)》规定,我国初中阶段的课程设置方式是( )。
【简答题】岩石是一种或多种矿物或岩屑组成的集合体,按其成因分成岩浆岩、沉积岩和()三大类。
【单选题】2001 年教育部颁布了(),并在全国 38 个试验区进行了基础教育体育课程改革实验,标志着第八轮体育课程改革的正式拉开帷幕。
C.
《 关于强化学校体育促进学生身心健康全面发展的意见 》
【判断题】岩石是由一种或多种矿物或岩屑组成的自然集合体,是各种地质作用的产物,是构成地壳的物质基础。
【单选题】Which chart is correct? DC--desktop computers, NC—notebook computers CC--cycle computers
【判断题】岩石是由一种或多种矿物或岩屑组成的有规律的集合体,是地质作用的产物。
【判断题】Desktop computers and portable computers both belong to microcomputers.