生根度

关于Meckel憩室的描述，哪些错误（）。

A.是先天性假性憩室

B.通常位于结肠末段

C.基底开口于肠系膜缘对侧

D.无独立血供

E.憩室内常有异位组织

辛亥革命后，中国社会生活发生了巨大变化。假如你是一位已经接受新生事物并生活在当时上海的某政府官员，你不可能[ ]

A．看商务印书馆印刷的学术著作

B．称呼上司为“老爷”

C．让自己的妻子穿旗袍

D．在报纸上看新闻

如图所示,以平面镜的高度为直径作一圆,使圆所在的平面与平面镜垂直,在圆周上有三个发光点a､b､c跟圆心的连线与平面镜的夹角分别为α､β､γ,人眼位于所在平面,在镜前一定范围内可以看到发光点a､b､c的像,下列判断正确的是(本题中像的观测范围是指边界光线间夹角)(    )

A．观测到a点像的范围最大

B．观察到c点像的范围最大

C．观察到a､b､c三点像的范围一样大

D．观察到a､b､c三点像的范围不一样大

矿山，建筑施工单位和危险物品的生产，经营，储存单位，应当设臵安全生产管理机构或配合（）

A、专职安全生产管理人员

B、安全生产人员

C、管理人员

D、主要负责人

A local-area network (LAN) is a communications network that (125) a variety of devices and provides a (126) for information exchange among those devices. The scope of the LAN is small typically a single building or a cluster (丛) of buildings. The LAN is usually owned by the same organization that owns the (127) devices. The internal data rate of LAN is at least several Mb/s.
The basic of LAN communication is broadcasting. At each station, there is a transmitter/receiver that communicates over a (128) shared, By other stations. A transmission from any one station is (129) to and received by all other stations.

A．broadcast

B．cable

C．control

D．interconnects

E．internet

F．meander

G．means

H．medium

I．modem

J．output switch relay