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单项选择题

常用的dB(A)声学计量单位反应下列入耳对声音的哪种特性？( )

A.时间计权
B.频率计权
C.最大声级
D.平均声级
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单项选择题
Light travels at a speed which is about a million times faster than the speed of sound. In one second, light travels about 300,000 km. But sound travels only 344m. You can get some idea of his difference by watching the start of a race. If you stand some distance away from the starter, you can see smoke comes from his gun before the sound reaches your ears.
This great speed of light gives us some strange facts. Sunlight takes about 8 minutes to reach us. If you look at the light of the moon tonight, remember that the light left the moon 1.3 seconds before it reached you. The nearest star is so far away that the light which you can see from it tonight started to travel towards you four years ago at a speed of nearly 2 million km per minute. In some case, the light from one of tonight's stars started on its journey to you before you were born.
Thus, if you want to be honest, you can say "The stars are shining to night?" You have to say“The stars look pretty. They were shining four years ago but their light has just reached Earth. "
If the information given in this passage is correct, when we look at a star at night ____.（　　
A.wewillnoticethatitisnotmoving
B.wecannottellwhetherornotitstillexists
C.itisfouryearsthatthelightwecanseewillreachus
D.itwillbebrighterthanthemoon
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除混凝土实心板外，混凝土用的粗骨料，其最大颗粒粒径不得超过构件截面最小尺寸的限值和不得超过钢筋最小净间距的限值分别为：( )
A.1/5，1/2
B.1/4，3/4
C.1/3，2/3
D.2/5，3/5
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不属于工程量清单编制依据的是：( )
A.工程设计图纸及相关资料
B.施工招标范围
C.地质勘探报告
D.施工占地范围
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