问题
选择题
下列日常生活中的物质,属于纯净物的是( )
A.酱油
B.食盐水
C.食醋
D.蔗糖
答案
由多种物质组成的物质,属于混合物;由一种物质组成的物质,属于纯净物.
A、酱油中含有水、氯化钠等物质,属于混合物;
B、食盐水中含有水和氯化钠,属于混合物;
C、食醋中含有水、醋酸等,属于混合物;
D、蔗糖是由一种物质组成的,属于纯净物.
故选D.
下列日常生活中的物质,属于纯净物的是( )
A.酱油
B.食盐水
C.食醋
D.蔗糖
由多种物质组成的物质,属于混合物;由一种物质组成的物质,属于纯净物.
A、酱油中含有水、氯化钠等物质,属于混合物;
B、食盐水中含有水和氯化钠,属于混合物;
C、食醋中含有水、醋酸等,属于混合物;
D、蔗糖是由一种物质组成的,属于纯净物.
故选D.
One day, Mr. White told the class that there would be a hobby show. It took all the students the whole morning to get ready for it. 1 , the laziest boy in the class. It was very difficult for the others to believe that he had a hobby. But to their surprise, 2 . Mr White was very happy. After school, Bob was going to take them back. “Bob, you can’t take them back until the others watch them this afternoon,” said Mr White. “But 3 , they are my brother’s,” he answered. “He doesn’t want them to be out of our home for long. He’s afraid that they will be lost.” “ 4 , not someone else’s!” Mr. White became a bit angry. But 5 . “Mr White, it’s true that I have a hobby. My hobby is watching my brother collecting shells.”
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