试述数控机床对伺服系统的要求

the bed.阅读理解 I’m John. This is my brother Jack. This is our room. This is my backpack. It’s on the bed. That’shis back pack. It’s on the chair. His computer gameis on it. Where’s my computer gameIs it on the chair, too No, it isn’t. It’s under it! Our computer is on thedesk. An alarm clock is next to it. Our booksaren’t on the desk. They’re in the bookcase. It’snext to the bed. 根据短文内容 ,判断下列句子的正 （）5. The books are in the bookcase.