问题
单项选择题
矿棉适宜的吸声厚度(cm)是()
A. 20
B. 5~15
C. 16~20
D. 2~4
答案
参考答案:B
解析:
通常情况下,矿棉板、矿棉砖的厚度多在50~120mm之间。
矿棉适宜的吸声厚度(cm)是()
A. 20
B. 5~15
C. 16~20
D. 2~4
参考答案:B
解析:
通常情况下,矿棉板、矿棉砖的厚度多在50~120mm之间。
在下列各句的空格内填上一个适当的完整的单词,该词的首字母已给。 小题1:In autumn the leaves of most trees turn y________. 小题2:There’s no b________ over the river. We have to cross it by boat. 小题3:It’s best to water plants either e________ in the morning or late at night. 小题4:Many children like spending much money in b________ beautiful pencil boxes. 小题5:Before you come into the room, please k ________ at the door.
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