Pitch is produced by frequency of vibration of the vocal cords. The higher the frequency, the higher the pitch.()
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瓦斯隧道瓦斯含量低于5%时,应每0.5-1h检测一次,瓦斯含量高于5%是,应每15min检测一次。
A. 正确
B. 错误
所收运的货物的最小体积长、宽、高合计不少于40厘米,最小的一边不得少于5厘米。()
A. 正确
B. 错误
为什么形状复杂的冲压和铆钉等冷塑性变形加工的工件多低碳钢,而工、模具用高碳钢?
A customer has 2 DS1s to add between adjacent nodes in a UPSR ring. What type of circuit should you recommend?()
A. VT circuits
B. STS circuits
C. VT tunnel circuits
D. 1:1 protection circuits
E. 1:N protection circuit