.z=1-i，所以z.z-z-1=（1+i）（1-i）-1-i-1=-i
故选B
句型转换。
1．We started music class at 7:30 today.(对画线部分提问)
__________ __________ you ___________music class today?
2. She has been doing homework since an hour ago．(对画线部分提问)
__________ __________ __________she__________ __________homework?
3. He began to listen to BBC English half an hour ago.(改为同义句)
He__________ __________ __________ __________ BBC English__________ __________ __________ __________．
4.I began to learn English at the age of five.(改为同义句)
I began to learn English__________ __________ __________ __________．
5.I went to the party, too.(改为否定句)
I__________ __________ __________ __________the party,__________．
慢性阻塞性肺气肿的体征有（）
A、叩诊为浊音
B、叩诊为鼓音
C、叩诊为实音
D、叩诊为过清音
