题干

某班级的同学想测定花生仁和核桃仁中的能量,于是,他们设置了如图所示的实验装置进行探究,各小组测得的实验数据如表.与实际数据相比都偏低.下列分析正确的是(  )

种子

种子质量(克)

水量(毫升)

燃烧前水温(℃)

燃烧后水温(℃)

花生仁

0.68

30

20

70

核桃仁

0.72

30

20

86


A:为了减少误差,选择的花生仁和核桃仁越大越好

B:为了保证数据的准确性,温度计的下端要接触到锥形瓶底部

C:实验数据偏低可能是计算错误,与热量无光

D:通过计算可知,每克花生仁含有的能量是9264.7焦,每克核桃仁含有的能量是11550焦

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答案(点此获取答案解析)

D

同类题2

Roald Dahl was one of the most successful writers of children's books. He sold millions of books all over the world. Many of his books have been made into films and videos. He is so famous that there is even a Roald Dahl Museum you can visit.

Roald Dahl was born in 1916 in Wales, Britain. His father was rich but he died when Roald was very young. Roald and his mother lived a hard life. He had to leave school and went to Africa where he worked for an oil company.

    In 1939 Roald became a pilot, but he had a bad accident. It made him limp(瘸的) for the rest of his life. After this, Roald went to America where he wrote a story about his experience as a pilot. It was so good that it was put in a magazine.

       Roald married an American film star. They bought a house in England and had five children. From 1960 to 1965,    ▲   : Theo, one of his children, was hit by a taxi and was seriously hurt. Olivia, one of Roald’s daughters, died of a strange illness. Soon after this, his wife also had a serious illness. It took her years to get completely better.

 Gradually Roald became more and more successful. He always did his writing in an old shed(棚) at the back of his house. He always sat in the same old armchair with a wooden board on his lap.

 “One of the nice things about being a writer,” he once said, “is that all you need is what you’ve got in your head and a pencil and a bit of paper.”

       In 1983 Roald wona big prize for his book The BFG. During his life, Roald wrote many famous books, such as Charlie and the Chocolate Factory, Matilda, Fantastic Mr. Fox

       After he died in 1990, Roald left money to help people with serious illnesses and those with problems with reading and writing.