问题 单项选择题 A1/A2型题

一穴肛原癌是指在齿线上方狭窄的环行区,由上皮细胞演变而发生,这种上皮细胞的类型是()

A.柱状上皮

B.移行上皮

C.鳞状上皮

D.混合上皮

E.肛管单层上皮

答案

参考答案:B

解析:齿线上方狭窄的环形区是胚胎一穴肛残余,在环形区有柱状上皮、鳞状上皮、移行上皮或三种混合上皮,由此区移行上皮发生的癌称一穴肛原癌。过去对此癌的组织学未完全了解,因而按癌的不同形态而命名,曾被称为未分化癌、基底细胞样癌、黏液表皮样癌、移行细胞癌、鳞化腺癌。近年通过电镜观察,确认本病是一种特殊起源的肿瘤。一穴肛原癌少见,占直肠肛管肿瘤1%。齿线及其上、下是其好发部位。Klotz报道372例中,44%位于齿线以下,38.9%位于齿线,13.3%位于齿线以上,3.8%部位不详。好发于40~60岁,女性较多见。故答案应选B。

单项选择题

As Philadelphia grew from a small town into a city in the first half of the eighteenth century, it became an increasingly important marketing center for a vast agricultural hinterland. Market days (1) the crowded city even more crowded, as farmers from within a (2) of 24 or more kilometers brought their sheep, vegetables, cider and other products for direct sale to the (3) . The High Street Market was continuously (4) throughout the period until 1736, (5) it (6) from Front Street to Third. By 1745 New Market was opened on Second Street. The next year the Callow Hill Market began (7) .

Along with market days, the (8) of twice-yearly fairs persisted in Philadelphia (9) after similar trading days had been discontinued in other colonial cities. The (10) provided a means of bringing handmade goods from (11) places to would-be buyers in the city. Linens and stockings from Germantown, (12) , were popular items.

Auctions were another popular (13) of trade. Because of the competition, retail (14) opposed these as well as the fairs. (15) governmental attempts to eradicate fairs and auctions were less than successful, the ordinary (16) of economic development was on the merchants’side, as increasing business specialization became the (17) of the day. Export merchants became differentiated from their importing counterparts, and specialty shops began to appear (18) general stores selling a variety of goods.

One of the reasons Philadelphia’s merchants prospered was because the surrounding area was undergoing tremendous economic and demographic growth. They did their business, (19) , in the capital city of the province, (20) to not only the governor and his circle, but citizens from all over the colony.

4()

A.envisioned

B.endangered

C.enriched

D.enlarged

单项选择题