中文摘要：

0→J→A→B→0是一个拟对角扩张.证明以下结论：（1）如果J和B具有弱可比性质,则A也具有弱可比性质;（2）如果J和B具有强消去性质,则A也具有强消去性质;（3）如果J和B具有n-无孔性质,则A也具有n-无孔性质.

英文摘要：

Let 0→J→A→B→0 be a quasidiagonal extension.We show the following results：（1）suppose that J and B have the weakly comparison properties,then A has the weakly comparison property.（2）suppose that J and Bhave the strictly cancellation properties,then A has the strictly cancellation property.（3） suppose that J and B have the n-unperforated properties,then A has the n-unperforated property.