语调。根据所给句子选择正确的语调。

A. 升调 B. 降调 C. 升、降调 D. 降、升调

(     )1. We have a nice house and a happy family.

(     )2. Are the gloves yellow or blue?

(     )3. They don't have computers.

( )4. Is this your cap?

( )5. He is my new friend.

急性化脓性骨髓炎早期手术的目的是

A．消灭死腔

B．减压和引流

C．清除死骨和窦道

D．切除病灶

E．预防病理性骨折