正确答案: A

有能量变化 物质的颜色和状态发生改变 有新物质生成 发光放热

题目：下列对化学变化的本质特征认识正确的是（ ）

解析：C

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举一反三的答案和解析：

[单选题]Mary always wanted to be a singer．(11) was the most important part in her life． Un-luckily， she had a (12) voice． Although she took lessons (13) many years， her voice didn't get better． It just got louder． Her teacher finally (14) teaching her， but she kept on practicing herself．One dayshedecided (15) a concert and invited her teacher to it． The teacher was very (16) about what to say after the concert． He knew it would be a (17)． one． At last he got an idea． When the concert (18) ， he went to see Mary． "Well，" said Mary， "What do you (19) my concert? "My dear， said the teacher． "You’ll never be (20) than you are tonight．

( )11．

Music

[单选题]59．

always

解析：59．B【解析】由句意“它总是值20元，即使把它扔在地上”可知应选B。