Given a voice signal [img=31x25]1803377a105a2ae.png[/img],if we transform the signal to a new signal [img=108x25]1803377a1936ebf.png[/img], what will the new signal [img=30x25]1803377a217e8d9.png[/img] be different from the original signal [img=31x25]1803377a2928967.png[/img]?
A: The length of [img=30x25]1803377a3149b0c.png[/img] will be extended, and the pitch will be higher.
B: The length of [img=30x25]1803377a3149b0c.png[/img] will be extended, and the pitch will be lower.
C: The length of [img=30x25]1803377a3149b0c.png[/img] will be compressed, and the pitch will be higher.
D: The length of [img=30x25]1803377a3149b0c.png[/img] will be compressed, and the pitch will be lower.
A: The length of [img=30x25]1803377a3149b0c.png[/img] will be extended, and the pitch will be higher.
B: The length of [img=30x25]1803377a3149b0c.png[/img] will be extended, and the pitch will be lower.
C: The length of [img=30x25]1803377a3149b0c.png[/img] will be compressed, and the pitch will be higher.
D: The length of [img=30x25]1803377a3149b0c.png[/img] will be compressed, and the pitch will be lower.
举一反三
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1802f060e2f728f.png[/img]+1=0｝ B: ｛x|[img=18x22]1802f060e2f728f.png[/img]<-x｝ C: ｛x|[img=18x22]1802f060e2f728f.png[/img]=0｝ D: ｛x|[img=18x22]1802f060e2f728f.png[/img]-1=0｝
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1803d021d498831.png[/img]+1=0｝ B: ｛x|[img=18x22]1803d021d498831.png[/img]<-x｝ C: ｛x|[img=18x22]1803d021d498831.png[/img]=0｝ D: ｛x|[img=18x22]1803d021d498831.png[/img]-1=0｝
- 下列4个集合中是空集的是（） A: ｛x|[img=18x22]1803d0240bcad39.png[/img]+1=0｝ B: ｛x|[img=18x22]1803d0240bcad39.png[/img]-x｝ C: ｛x|[img=18x22]1803d0240bcad39.png[/img]=0｝ D: ｛x|[img=18x22]1803d0240bcad39.png[/img]-1=0｝
- 下列关系式中不正确的是 A: 0[img=12x17]1802db3ca94b21c.png[/img]Æ B: 1[img=12x17]1802db3ca94b21c.png[/img]{1，4} C: -1[img=12x17]1802db3ca94b21c.png[/img]{x|x+1=0} D: 2[img=12x17]1802db3ca94b21c.png[/img]{x|x>0}
- 在下列命题中:如果f(x)=[img=28x44]17e0bf9914bb2f1.png[/img],那么[img=27x29]17e0bf97582597b.png[/img]f(x)=0;如果f(x)=[img=28x44]17e0bf992111a1c.png[/img],那么[img=27x29]17e0bf97582597b.png[/img]f(x)=0;如果f(x)=[img=55x44]17e0bf992d8de0a.png[/img],那么[img=29x29]17e0bf9939482bb.png[/img]f(x)不存在;如果f(x)=[img=87x53]17e0bf99450fa82.png[/img],那么[img=27x29]17e0bf97582597b.png[/img]f(x)=0。其中错误命题的个数是( A: 0 B: 1 C: 2 D: 3