问题 填空题
观察下面各等式,找出规律,
1
2
+
3
1
=
2+3+2
1×2
2
3
+
4
2
=
8+6+2
2×3
3
4
+
5
3
=
18+9+2
3×4
4
5
+
6
4
=
32+12+2
4×5

第n个等式为______.
答案

根据题中所给的式子可知,等式的左边第一个加数的分子和第二个加数的分母相等,且第一个分数的分子,分母和第二个加数的分子是3个连续的整数;等式的右边分母的规律是两个连续整数的积n(n+1),分子的规律是2n2+3n+2.

所以第n个等式为

n
n+1
+
n+2
1
=
2n2+3n+2
n(n+1)
(n是正整数).

阅读理解

阅读理解。

                                                                       NEWS BRIEF

     ●Prime Minister Tony Blair new allegations (指控) on Thursday that he misled Parliament and the public in

making the case for the war in Iraq after he disclosed his chief legal adviser's written opinion raising questions

about the legality (合法) of the war.

     ●U.S. Forest Service officials are reminding people to stay off Forest Service roads that are closed. The

fine for disobeying the rule of road closures is a maximum of $5,000 fine and/ or six months in prison. Those who enter the area and cause road damage may also be required to pay for repairs.

     ●In a second study presented at the meeting, scientists from the UK and Denmark showed that even a few

days of high temperatures can severely reduce production of crops such as wheat, soybeans, rice and

groundnuts, if it occurs when the plants are flowering.

     ●A bomb exploded in Thailand's mainly Muslin south on Sunday, killing two policemen and wounding three

others, a day after Thailand's queen condemned those behind a 15-month wave of violence (暴力).

     ●Mechanicsburg 3, West York 1: Ken Stamper and Rusty Bowman had seven kills each, and Ryan Warfield

had six to lead the Wildcats past the Bulldogs, 25-11, 25-15, 15-25, 25-23, in a non-league match.

1. The news brief covers _______.

A. war, law, violence, culture and agriculture

B. sports, war, violence, politics and climate

C. politics, culture, violence, climate and sports

D. violence, sports, politics, law and agriculture

2. From the news brief, we can learn that ________.

A. the Bulldogs defeated the Wildcats by 3-1 in a non-league match

B. Forest Service roads are closed for repairs before they are opened again

C. quite a few violent accidents happened in Tailand before the latest one

D. the British people think the decision made by Blair about the war is of legaliry

3. According to the U.S. Forest Service officials, those who enter the area and damage the closed roads ______.

A. shall have to pay a $ 5,000 fine for the repairs to them

B. shall be fined or put in prison, and may pay for the repairs

C. shall be fined $ 5,000 and kept in prison for six months

D. shall pay a fine and repair the roads as a punishment

4. The study of the scientists from the UK and Denmark is about _______.

A. the importance of climate and the growth of crops

B. the damage caused by high temperatures to some crops

C. the relationship between crops flowering and high temperatures

D. the effect of high temperatures on the production of some crops

单项选择题