In fact, there was hardly any activity or social event that could not be set to Music. Weddings, births, christening, funerals, picnics, parades-- 21 had their musical accompaniment.
After the American Civil War (1860-1865), the Negroes had gained their freedom and were ready 22 a new type of music, 23 that would preserve their musical traditions but be fast and happy 24 their 25 freedom. They wanted something they could play as professional musicians for both black and white audiences. Jazz was the answer. It combined themes from Negro work songs, spirituals and blues, set to a fast beat, 26 the musicians improvising (即兴而作) as they went along, like the funeral marching bands. To be good, a musician had not only to remember his part but also 27 able to invent new variations on the spur (激励) of the moment.
Jazz 28 the people, but popular 29 is changed many times in form, style, and tempo. Each change added something 30 .
21.
A. which
B. that
C. all
D. those
第4题
抽象类论述中,不正确的是()。
A 如果一个类至少有一个纯虚函数,那么该类为抽象类。
B 抽象类只能用作其他类的基类,不能建立抽象类对象。
C 抽象类可以用来定义指针。
D 抽象类可以作为某个函数的返回类型。
第5题
下列关于抽象类和纯虚函数的说法错误的是()。
A.抽象类只能作为基类使用,而纯虚函数的实现由派生类给出
B.抽象类是指具有纯虚函数的类
C.纯虚函数是一种特殊的虚函数,它允许没有具体的实现
D.一个基类的说明中有纯虚函数,则该基类的派生类一定不再是抽象类
第6题
关于抽象类的下列描述中,错误的是()。
A 如果一个类至少有一个纯虚函数,那么该类为抽象类。
B 抽象类只能用作其他类的基类,不能建立抽象类对象。
C 抽象类可以用来定义指针。
D 抽象类可以作为函数的参数类型。
第8题
下列关于抽象类的表述中正确的是()。
A.派生类必须要实现作为基类的抽象类中的纯虚函数
B.抽象类的成员函数至少有一个没实现
C.抽象类不可能用来定义对象
D.派生类不能成为抽象类
第9题
A.纯虚函数是一种特殊的虚函数,它没有具体的实现
B.抽象类是指具有纯虚函数的类
C.一个基类中说明具有纯虚函数,该基类的派生类一定不再是抽象类
D.抽象类只能作为基类来使用,其纯虚函数的实现由派生类给出
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