脑脊液每小时分泌量约（） A.10ml B.5ml C.15ml D.20ml E.

容易出现基托不密合的是

A．基托过薄
B．人工牙磨耗
C．开盒过早致基托变形
D．模型不准确
E．人工牙盖峙部蜡质未去净

（）是改正轨距。

甲、乙两块土地，其区位及实物状况都基本一样。甲地块土地单价为506元/m²，容积率为1.5，土地使用年限为50年；乙地块土地单价为820元/m²，容积率为2.4，土地使用年限为70年。在用楼面地价来判断甲、乙两地块的投资价值时，若土地报酬率为8%，则下列表述中正确的有（）。

A．乙地块比甲地块贵

B．甲地块的70年使用权楼面地价低于341.67元/m²

C．甲地块与乙地块的楼面地价相等

D．乙地块的70年使用权楼面价高于340元/m²

E．甲地块比乙地块贵

圆：半圆：半径

A．三角形：正方形：高
B．正方形：菱形：对角线
C．长方形：矩形：角
D．梯形：五边形：腰

Ragtime is a musical form that synthesizes folk melodies and musical techniques into a brief quadrille-like structure, designed to be played—exactly as written—on the piano. (46) A p analogy exists between European composers like Ralph Vaughan Williams and Edward Grieg, who combined folk tunes and their own original materials in larger compositions and the pioneer composers in the United States. Composers like Scott Joplin and James Scott were in a sense collectors or musicologists, collecting dance and folk music in Black communities and consciously shaping it into brief suites or anthologies called piano rags.

It has sometimes been charged that ragtime is mechanical. For instance, Wilfred Mellers comments, "rags were transferred to the pianola roll and, even if not played by a machine, should be played like a machine, with meticulous precision." (47)However, there is no reason to assume that ragtime is inherently mechanical simply because commercial manufacturers applied a mechanical recording method to it, the only way to record pianos at that date. Ragtime’s is not a mechanical precision, and it is not precision limited to the style of performance. It arises from ragtime’s following a well-defined form and obeying simple rules within that form.

The classic formula for the piano rag disposes three to five themes in sixteen-bar strains, often organized with repeats. (48)The rag opens with a bright, memorable strain or theme, followed by a similar theme, leading to a melody of marked lyrical character, with the structure concluded by a lyrical strain that parallels the rhythmic developments of the earlier themes. The aim of the structure is to rise from one theme to another in a stair-step manner, ending on a note of triumph or exhilaration. Typically, each strain is divided into two 8-bar segments that are essentially alike, so the rhythmic-melodic unit of ragtime is only eight bars of 2/4 measure. (49) Therefore, not concerned with development of musical themes, the ragtime composer instead sets a theme down intact, in finished form, and links it to various related themes that are brief with clear melodic figures. Tension in ragtime compositions arises from a polarity between two basic ingredients: a continuous bass—called by jazz musicians a boom-chick bass--in the pianist’s left hand, and its melodic, syncopated counterpart in the right hand.

Ragtime remains distinct from jazz both as an instrumental style and as a genre. Ragtime style stresses a pattern of repeated rhythms, not the constant inventions and variations of jazz. (50)As a genre, ragtime requires strict attention to structure, not inventiveness or virtuosity, existing as a tradition, a set of conventions, a body of written scores, separate from the individual players associated with it. In this sense ragtime is more akin to folk music of the nineteenth century than to jazz.

(46) A p analogy exists between European composers like Ralph Vaughan Williams and Edward Grieg, who combined folk tunes and their own original materials in larger compositions and the pioneer composers in the United States.