金属薄板、船体、飞机外壳等常会因剧烈的振动辐射较强的噪声,采取以下哪种方法可有效降噪()?
A. 打孔
B. 涂抹阻尼材料
C. 加厚
D. 提高强度
查看答案
树叶落下的沙沙声的声压级约为()。
A. 5分贝
B. 10分贝
C. 20分贝
D. 40分贝
The TTS run will demonstrate ()the car can take curves as fast as a human driver—without driving off a cliff.
A. as
B. that
C. when
D. whether
Consequently, more than 100 cities in the United States still have levels of carbon monoxide, particulate matter, and ozone that()legally established limits.
A. succeed
B. proceed
C. exceed
D. excess
Your speech class will give you an opportunity to gain confidence and make your nervousness work for you()against you.
A. more than
B. apart from
C. rather than
D. instead