化脓性骨髓炎是涉及什么组织的感染（）. A.骨髓 B.骨皮质和骨髓 C.骨膜和骨髓

— I will come to attend your lecture at 10:00 tomorrow.

— I’m sorry, by then my lecture will have ended and I _____ in my office.

A．am working

B．will work

C．will be working

D．will have worked

— Can I borrow your car for a while?

— Sorry, my car was damaged yesterday and it ______ now?

[      ]

A. is repaired

B. is being repairing

C. is being repaired

D. is repairing

旅游行政管理部门接到旅游者投诉后应当在10日内做出是否受理的决定，决定受理的，应当在30日内做出处理决定，并答复投诉者。( )

关系代数的五个基本操作可直接转换成元组关系演算表达式，它们是：并、差、笛卡尔积、投影和______

A．交
B．选择
C．自然连接
D．除法

呃逆的主要临床表现是（）

A.喉间呃呃连声，声短而频

B.呃逆令人不能自止

C.呃逆可以控制

D.以上均是

E.以上均不是