头发呈波状，嘴唇薄，体毛较多的人种为（ ） A．棕色人种 B．黑色人种 C．黄色

Standard English is the variety of English which is usually used in print and which is normally taught in schools and to non-native speakers learning the language. It is also the variety which is normally (1) by educated people and used in news broadcasts and other (2) situations. The difference between standard and nonstandard, it should be noted, has (3) in principle to do with differences between formal and colloquial (4) ; standard English has colloquial as well as formal variants.

(5) , the standard variety of English is based on the London (6) of English that developed after the Norman Conquest resulted in the removal of the Court from Winchester to London. This dialect became the one (7) by the educated, and it was developed and promoted (8) a model, or norm, for wider and wider segments of society. It was also the (9) that was carried overseas, but not one unaffected by such export. Today, (10) English is arranged to the extent that tile grammar and vocabulary of English are (11) the same everywhere in the world where English is used; (12) among local standards is really quite minor, (13) the Singapore, South Africa, and Irish varieties are really very (14) different from one another so far as grammar and vocabulary are (15) .Indeed, Standard English is so powerful that it exerts a tremendous (16) on all local varieties, to the extent that many of long-established dialects of England have (17) much of their vigor and there is considerable pressure on them to be (18) . This latter situation is not unique (19) English: it is also true in other countries where processes of standardization are (20) .But it sometimes creates problems for speakers who try to strike some kind of compromise between local norms and national, even supranational ones.

12（）

A.variation

B.standardization

C.unification

D.transformation

有关脑静脉系统分类，下列叙述正确的是()

A．大脑浅静脉主要包括大脑上，中，下静脉

B．大脑浅静脉主要汇集整个大脑的皮质血液，并注入大脑深静脉和静脉窦

C．大脑深静脉主要是大脑大静脉包括大脑内静脉和基底静脉

D．基底静脉主要汇集纹状体的下部、丘脑、丘脑下部和中脑上部的血液，并注人大脑大静脉

E．静脉窦主要汇集大脑半球的血液，并通过颈静脉孔注入颈静脉

已知分式的值恒小于1，那么实数k的取值范围是（）。

A.k＞1

B.k≤3

C.1＜k＜3

D.1≤k≤3

二次函数y=ax²+bx+c的值恒为正，则a，b，c应满足（　　）

A．a＞0，b²-4ac＞0

B．a＞0，b²-4ac＜0

C．a＜0，b²-4ac＞0

D．a＜0，b²-4ac＜0

胫骨中下1/3段骨折愈合较慢的主要原因是

A．附近的主要血管损伤

B．附近的周围神经损伤

C．远骨折段血液供应减少

D．远骨折段完全丧失血液供应