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问题 选择题
已知直线y-1=k（x-1）恒过定点A，若点A在直线mx+ny-1=0（m，n＞0）上，则
1
m
+
1
n
的最小值为（　　）
A．2B．
1
2
C．4D．
1
4
答案

由

x-1=0
y-1=0
，得：
x=1
y=1
．

所以，直线y-1=k（x-1）恒过定点A（1，1）．

又点A在直线mx+ny-1=0（m，n＞0）上，

所以，m+n=1．

则

1
m
+
1
n
=(
1
m
+
1
n
)(m+n)=2+
n
m
+
m
n
．

因为m，n＞0，

所以，

1
m
+
1
n
=2+
n
m
+
m
n
≥2+2
n
m
•
m
n
=4．

当且仅当m=n=

1
2
时等号成立．

故选C．

单项选择题

耳后骨膜下脓肿的临床表现不包括（）。

A.局部及全身感染的表现

B.瘘管试验阴性

C.耳后脓肿形成

D.Growe试验阳性

E.穿刺可抽出脓液
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问答题

The first mention of slavery in the statutes of the English colonies of North America does not occur until after 1660--some forty years after the importation of the first Black people. Lest we think that slavery existed in fact before it did in law, Oscar and Mary Simon assure us that the status of Black people down to the 1660’s was that of servants. (46) A critique of the Simons’ interpretation of why legal slavery did not appear until the 1660’s suggests that assumptions about the relation between slavery and racial prejudice should be reexamined, and that explanations for the different treatment of Black slaves in North and South America should be expanded.

(47) The Simons explain the appearance of legal slavery by contending that, during the 1660’s, the position of White servants was improving relative to that of Black servants. Thus, the Simons argue, Black and White servants, heretofore treated alike, each attained a different status. There are, however, important objections to this argument. First, the Simons cannot adequately demonstrate that the White servant’s position was improving during and after the 1660’s; several acts of the Maryland and Virginia legislatures indicate otherwise. Another flaw in the Simons’ interpretation is their assumption that prior to the establishment of legal slavery there was no discrimination against Black people. It is true that before the 1660’s Black people were rarely called slaves. But this should not overshadow evidence from the 1630’s on that points to racial discrimination without using the term slavery. Such discrimination sometimes stopped short of lifetime servitude or inherited status--the two attributes of true slavery--yet in other cases it included both. (48) The Simons’ argument excludes the real possibility that Black people in the English colonies were never treated as the equals of White people.

This possibility has important ramifications. (49) If from the outset Black people were discriminated against, then legal slavery should be viewed as a reflection and an extension of racial prejudice rather than, as many historians including the Simons have argued, the cause of prejudice. In addition, the existence of discrimination before the advent of legal slavery offers a further explanation for the harsher treatment of Black slaves in North than in South America. (50) Frey and Terry have rightly argued that the lack of certain traditions in North America--such as a Roman conception of slavery and a Roman Catholic emphasis on equality--explains why the treatment of Black slaves was more severe there than in the Spanish and Portuguese colonies of South America. But this cannot be the whole explanation since it is merely negative, based only on a lack of something.

49（）
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