问题 问答题

如图,质量是1kg的物体沿斜面匀速下滑,请用力的示意图画出物体所受到的重力.

答案

物体的重力为:G=mg=1kg×9.8N/kg=9.8N;过物体的重心沿竖直向下画一条带箭头的线段,并且标出重力的大小;如图所示:

解答题
阅读理解

“Racism (种族歧视) is a grown-up disease,” declares the saying on Ruby Bridge’s website along with a photo of Mrs. Bridge today, a 6-year-old girl four decades ago. In the photo, she is walking up the steps of the William Frantz Public School in New Orleans, a little black girl accompanied by two officers who protect her on her way to school.

Her name then was Ruby Nell. It was Nov. 14, 1960. She was the first black child to enroll at this all-white elementary school according to the court order to desegregate in New Orleans schools. Her story is moving -- she was a very courageous child -- and remains a significant proof against intolerance (不宽容) of all kinds. Ruby’s photo brings out another powerful image on her website: Norman Rockwells symbolic painting for Look magazine on Jan. 14, 1964, “The Problem We All Live With.”

Rockwell was an illustrator of exceptional skill and charm. He produced a vast number of unforgettable images over a long career, many of them involving children. His American kids are innocent and appealing, but often, at the same time, decidedly naughty. His method was to photograph his models, and the resulting paintings were photographic. But it is revealing to see how the artist slightly changed facial expressions from photo to oil painting in order to make his paintings communicate with the viewer. Communication, even persuasion, lay at the back of his work; this was art for effect.

“The Problem We All Live With” belongs to Rockwell’s later work, when he began openly showing his strong belief in liberty. This is a highly persuasive image. Before he arrived at the final copy, one sketch (草图) shows the little girl closer to the two officers following her than to those in front. In the finished picture, the girl seems more determined, independent, and untouched. The unfriendly tomatoes thrown on the wall are behind her now, and she, is completely unaffected.

小题1:Ruby Nell was protected by officers on her way to school, because   .

A.she was a little fighter against racism

B.she was very young, short and timid

C.she was the first black to study in an all-white school

D.she was chosen by the com t0be’wi’th white children小题2:According to the passage, “The Problem We All Live With” is a(n)     .

A.social program for American children

B.famous painting by Norman Rockwell

C.photo displayed on Ruby Bridges’ website

D.exhibition at the Norman Rockwell Museum小题3:The word “desegregate” in paragraph 2 probably means“   ”.

A.fight against the white

B.end racial separation

C.struggle for freedom

D.stop the black-white conflict小题4:The main topic of this passage is   .

A.how Rockwell encouraged Ruby to fight against racism

B.how Ruby won her fight to go to an all-white school

C.how Rockwell expressed his protest in .Iris work

D.how persuasive Rockwell’s earlier work of art is