汽车正常行驶过程中所受到的滚动阻力,主要是由于车轮滚动时轮胎与路面的变形产生的,其数值的大小与汽车总重力、轮胎结构和气压以及路面的性质有关。
参考答案:对
阅读理解。
Many years ago, there was a family named Franklin. They lived in Boston. There
were five girls and six boys in the family. On a January day in 1706 another baby boy was born. The boy's mother and her husband gave the boy a name-Benjamin.
Benjamin was the brightest of all the children. He could read when he was five and he could write by the time he was seven. When he was eight, he was sent to school.
In school, Benjamin had been good at reading and writing but not good at maths.
He read all his father's books. And whenever (无论何时) he had a little money, he spent it on a book. He liked books. They told him how to do something. At that time he invented the paddles (桨形工具) for swimming.
1. The Franklins lived in .
A. England
B. America
C. France
D. Australia
2. There were children in the family.
A. five
B. six
C. eleven
D. twelve
3. Benjamin was born in the month of the year 1706.
A. first
B. sixth
C. seventh
D. fifth
4. Benjamin maths when he was in school.
A. did well in
B. did well at
C. didn't do well in
D. didn't do well at
5. Benjamin much money books.
A. spent, on
B. cost, buying
C. took, buy
D. pay, off
急性脊髓炎最常累及的脊髓节段是()。
A.颈1~4
B.颈5~8
C.胸3~5
D.胸10~12
E.腰2~4