A: Aren’t we supposed to have the meeting begun at 9 Where is the chair
B: ().

A. You know our director. He is always behind schedule.

B. I know it’s very later

C. No. I’ll have it tomorrow, not today.

D. See you then.

慢性髓细胞白血病急变时，最可靠的染色体变化是（）

A.ph染色体

B.出现非整倍体

C.出现假二倍体

D.出现除ph染色体以外的附加染色体

E.以上均不对