问题 单项选择题 B型题

牙菌斑中最厚的一层是()

A.基底层

B.中间层

C.表层

D.浅层

E.深层

答案

参考答案:B

解析:牙菌斑的基本结构从里到外共分为三层:表层又称为外层,其结构疏松,细菌组成复杂,变化较大,同时含有食物残渣、上皮细胞等;中间层是牙菌斑最厚的一层,可见由丝状菌、球菌、杆菌相形成的栅栏状结构,是牙菌斑的主体;基底层是牙菌斑紧靠牙面的一层无细胞的均质性结构。

问答题
单项选择题

The United States is usually given credit for creating and developing the musical comedy as it is known today. The first musical shows were based (1) everyday American life and the (2) development of the form took place in the United States for more than half a century. (3) the early 1970s, (4) , the London theater has (5) the Broadway stage.

The Black Crook, which opened at Niblo’s Garden in New York City on Sept. 12, 1866, is usually (6) as the inspiration for musical comedy. A troupe of French ballet dancers (7) to be stranded in New York without work (8) a fire damaged the theater (9) they had been booked. In order to keep a (10) to them, the theater producer put the dancers into a melodrama written by Charles M. Barres.

The first stage production that was (11) a musical comedy was a show that was (12) from the Prince of Wales Theater to the Gaiety Theater in London in 1892. Staged by George Edwards, the show called In Town featured a chorus line of Gaiety Girls. The (13) year A Gaiety Girl was equally successful, and a (14) of the show played in New York in the same year. When it was (15) in newspapers, it was designated a musical comedy and regarded as a new (16) of entertainment.

It did not take the form long to (17) in the United States. Almost (18) one of the most renowned talents of the American stage went to work on his own musicals. The singer-dancer George M. Cohan staged Little Johnny Jones in 1904. Cohan, (19) own life story was made into the musical George M (1968), also wrote the books, words, and (20) for Forty-five Minutes from Broadway ( 1906 ), The Little Millionaire ( 1911 ), The Song and Dance Man ( 1923 ), and American Born (1925).

6()

A.thought

B.believed

C.credited

D.said