倾角为θ的斜面,长为l ,在顶端水平抛出一个小球,小球刚好落在斜面底端,如图所示

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问题:

倾角为θ的斜面,长为l ,在顶端水平抛出一个小球,小球刚好落在斜面底端,如图所示,那么小球的初速度 v0 的大小为

[ ]

A.  

B.

C.  

D.

考点:平抛运动
题型:不定项选择

一般耳廓的发育几岁时已达到成人的85%()

A.4岁

B.5岁

C.6岁

D.7岁

E.8岁

题型:不定项选择
阅读理解。
     Bill Gates is head of the software company Microsoft and one of the world's richest men. He was born
on October 28, 1955 and grew up in Seattle with his two sisters. He was a very bright boy. Science and
math were his two favorite subjects at school. And he dreamed of being a scientist.
     Bill first started to play on computers at the age of 13. At that time, a computer was a very large machine.
Once he was interested in a very old computer. He and some of his friends spent as much time as possible on
computers. In the end, they worked out a software program. Bill sold it for 4,200 dollars when he was only 17.
     In 1973, Bill went to Harvard University. In 1975, Bill and his partners developed a software program
called BASIC. This was not the first program ever created, but its inventors were the first to decide that people who wanted to use it should pay for it. BASIC was a success. Then Bill left Harvard to work for Microsoft, a
company he started in 1975 with his boyhood friend Paul Allen. They thought the computer would come into
every office and every home soon. So they began developing software for personal computers. They improved
the software to make it easier for people to use computers. After many years of hard work, Microsoft becomes one of the most successful companies. And Bill Gates also becomes one of the richest businessmen in the
world.
Information about Bill Gates Date of birth: October 28, 1955
Official position: Head of Microsoft
Dream job in the childhood:                        1. ______________
Thing first done in1968:                             2. ______________
Name of the software program:                  3. ______________
Reason for developing personal software:    4. ______________
Achievements:                                          5. ______________
题型:不定项选择
已知x、y满足方程组
x+3y=9
3x+y=-1
,则代数式x+y的值为______.
题型:不定项选择

下列物质在空气中燃烧,主要现象描述错误的是 [ ]

A.红磷燃烧产生大量白烟

B.甲烷燃烧产生淡蓝色火焰

C.硫燃烧产生蓝紫色火焰

D.氢气燃烧的火焰是淡蓝色的

题型:不定项选择

第四方物流(4PL)

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