已知二次函数y=ax2+bx+c(a,b,c为常数),x与y的部分对应值如下表,

题型:填空题

问题:

已知二次函数y=ax2+bx+c(a,b,c为常数),x与y的部分对应值如下表,则当x满足的条件是______时,y>0.
x-2-10123
y-6-6020-6
考点:数学常识二次函数的定义
题型:填空题

It was ________ he came back from Africa that year ________ he met the girl he would like to marry.[ ]

A. when; then  

B. not; until

C. not until; that  

D. only; when

题型:填空题

健康成人白细胞正常值为( )

A.(5~10)×10 9/L

B.(4.5~11)×10 9/L

C.(4.5~10)×10 9/L

D.(4~10)×10 9/L

E.(4~11)×10 9/L

题型:填空题

What is your favorite color? Do you like yellow, orange, or red? If you do, you must be an active person who enjoys life. Do you like blue? Then you are probably quiet, shy, and would rather follow than lead.

Colors do influence our moods (情绪). A yellow room makes most people feel more cheerful and more relaxed than a dark green one; and a red dress brings warmth and cheer to the saddest winter day. On the other hand, black is depressing(令人压抑的). There was a black bridge over the Thames River, near London. The number of people who killed themselves on that bridge used to be larger than on any other bridge in the area -- until it was repainted green.

Light and bright colors make people not only happier but also more active. In the factory, the workers will work better, harder, and have fewer accidents when their machines are painted orange rather than black.

小题1:An active person may like ____   

A.yellow, orange, or red

B.yellow, black, or red

C.orange, blue, or black

D.black, red, or orange小题2:Most people feel more __ in a yellow room than in a dark green one.

A.tired

B.bored

C.worried

D.relaxed小题3:More people killed themselves on the black bridge than on any other bridge probably because ____

A.the bridge was very tall

B.the bridge was too crowded

C.people didn't like the bridge

D.the color of the bridge was depressing小题4:In the factory, when the machines are painted orange, the workers will work __

A.worse

B.harder

C.more slowly

D.more angrily

题型:填空题

给定的IP地址为192.55.12.120,子网掩码是255.255.255.240,那么网号是______,主机号是______,直播的广播地址是______。如果主机地址的头10位用于子网,那么184.231.138.239的子网掩码是______。如果子网掩码是255.255.192.0,那么下面主机______必须通过路由器才能与主机129.23.144.16通信。

A.0.0.0.112
B.0.0.0.120
C.0.0.12.120
D.0.0.12.0

题型:填空题

影响教学媒体选择的最重要因素是()。

A.实际约束和环境因素

B.教学目标和学科内容

C.学习任务和学习者

D.教师态度和教学方法

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