—It's very important for you to arrive on time.

—I ____ be there at seven o'clock, I promise.[ ]

A. will

B. can

C. must

D. should

男性，30岁，1周来发热伴皮肤出血点。化验血呈全血细胞减少，骨髓检查增生极度活跃，原始细胞占骨髓非红系有核细胞的40％，各阶段粒细胞占50％，各阶段单核细胞占30％，诊断急性白血病，其FAB分类的类型是

A．M1

B．M2

C．M4

D．M5

E．M6