—What's wrong with you? — .A. I don't li

患者下颌缺失，铸造支架义齿修复，RPI卡环，舌杆大连接体。义齿戴用1周后，主诉义齿压痛，基牙咬痛。查：舌系带根部小溃疡，叩(+)，义齿各部位密合，咬(作图)不高

舌系带根部溃疡的原因（）。

A．义齿前后翘动

B．义齿摘戴困难

C．义齿下沉

D．舌杆位置过低

E．舌杆未缓冲

下列物质前者属于纯净物，后者属于混合物的是（   ）

A．澄清石灰水、矿泉水

B．水银、生铁

C．石灰石、石油

D．氯酸钾、过氧化氢

四边形的内角和与外角和的和是（　　）

A．360°

B．180°

C．540°

D．720°

An Intranet is (71) the application of Internet technology within an internal or closed user group．Internets are company and not do not have a (72) connection to the Internet．Usedproperly an Internet is highly effective corporate tool，capable of regularly (73) information toempower the workforce with the information needed to perform their roles．Used in this Way，Internet represent a step towards the (74) office．

A．painless

B．painness

C．paperless

D．paperness

管饲法分类有哪些？