【判断题】超声波从Z1入射到Z2界面的声强反射率和声强透过率等于超声波从Z2入射到Z1界面的声强反射率和声强透过率。
【单选题】The bandwidth of an amplifier is ( ).
A.
the range of frequencies over which gain remains relatively constant
B.
the range of frequencies between the lower and upper 3 dB frequencies
C.
the range of frequencies found using
【多选题】The bandwidth of an amplifier is ( ).
A.
the range of frequencies over which gain remains relatively constant
B.
the range of frequencies between the lower and upper 3 dB frequencies
C.
the range of frequencies found using
【判断题】(09)根据安全防护要求,清洗喷枪时配戴耐溶剂手套(厚的)或防溶剂手套(薄的)均可。