今天数学课上,老师讲了多项式的加减,放学后,小明回到家拿出课堂笔记复习老师课上讲

题型:选择题

问题:

今天数学课上,老师讲了多项式的加减,放学后,小明回到家拿出课堂笔记复习老师课上讲的内容,他突然发现一道题:(x2+3xy)﹣(2x2+4xy)=﹣x2【】.此空格的地方被钢笔水弄污了,那么空格中的一项是[ ]

A.﹣7xy

B.7xy

C.﹣xy

D.xy

考点:整式的加减
题型:选择题
设椭圆
x2
m2
+
y2
n2
=1
(m>0,n>0)的一个焦点与抛物线x2=4y的焦点相同,离心率为
1
3
则此椭圆的方程为(  )
A.
x2
9
+
y2
8
=1
B.
x2
8
+
y2
9
=1
C.
x2
36
+
y2
32
=1
D.
x2
32
+
y2
36
=1
题型:选择题

单词拼写。

根据所给首字母和中文提示完成各句,使句意通顺。

1. There was adequate sunshine in Xinjiang this summer, a_____ for the extremely sweet grapes in this area.

2. The government expressed their apology to the victims in the explosion on Nov.2 in Fuquan, c______

    each a lot to the satisfaction of their families.

3. Doracy is coming to China, and he finds from the Internet that one pound e______ more than ten yuan now.

4. Not r_____ to his fate, the statesman struggled to win the election by increasing the employment rate.

5. She s_____ her family life to her career,for it was her ambition at college to be a world-famous CEO.

6. Too long a time of _____ (暴露)to the sun does harm to our skin.

7. Engineers are researching ways to approach sources of _____ (替代的)energy for our next generations.

8. Under no _____ (情况) should such destruction be allowed to happen to historic sites.

9. With the use of solar energy, the company is now running ______ (顺利).

10. The Greek government is working hard to create more jobs for the ______ (失业的)people.

题型:选择题

假定某产品的单位贡献边际大于零,在其他条件不变的情况下,本期的销售量比上期减少,如按变动成本法确定营业利润,本期营业利润与上期相比将()

A.增加

B.减少

C.不变

D.可能增加也可能减少

题型:选择题

地温梯度测井必须()。

A.下测

B.上测

C.上、下测

题型:选择题

下列具有起昙现象的表面活性剂是

A.硬脂酸钠

B.月桂醇硫酸钠

C.硬脂醇硫酸钠

D.司盘-80

E.吐温-20

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