单开道岔由（)组成。

A.南方语系

B.汉藏语系

C.北方语系

D.阿尔泰语系

. This does not mean that we can sit down today and outline the future course of the universe with anything like certainty. There are still too many things we don't know about the way the universe is put together. But we do know exacdy what information we need to fill in our knowledge, and we have a pretty good idea of how to go about getting it. Perhaps the best way to think of our present situation is to imagine a train coming into a switchyard(调车场). All of the switches(转辙器) are set before the train arrives, so that its path is completely determined. Some switches we can see, others we cannot. There is no ambiguity if we can see the setting of a switch; we can say with confidence that some possible futures will not materialize and others will. At the unseen switches, however, there is no such certainty. We know the train will take one of the tracks leading out, but we have no idea which one. The unseen switches are the true decision points in the future, and what happens when we arrive at them determines the entire subsequent course of events.

When we think about the future of the universe, we can see our "track" many billions of years into the future, but after that there are decision points to be dealt with and possible fates to consider. The goal of science is to reduce the ambiguity at the decision points and find the true road that will be followed.

According to the passage, it is difficult to be certain about the distant future of the universe because we______.

A．have too many conflicting theories

B．do not have enough funding to continue our research

C．are not sure how the universe is put together

D．have focused our investigations on the moon and planets

由两部分组成：与该联系有关的键码属性(集)； ______。

A.二进制数只由两位数组成

B.二进制转化为八进制时，当分组不足3位，分别向高位或低位补0凑成3位

C.十进制转化为其它进制时，其整数部分和小数部分在转换时需作不同的计算

D.八进制转化为十六进制时，可以通过二进制数作为中间桥梁，先转化为二进制数，再转化为十六进制

E.二进制转化为十六进制时，当分组不足4位，分别向高位或低位补0凑成4位

773.15K时，的平衡常数为8.39×10^-4Pa^-1。当SO₂=7.8%，O₂=10.8%，N₂=81.4%(体积分数)的气体由硫铁烧炉进入转化器时，一部分SO₂变为SO₃达到平衡而导出。若此时转化器内保持101.325kPa、773.15K，试求导出的气体组成。

阻网络连接时，由分压器产生输出信号。试画出在CP时钟作用下D，Q₀～Q₇及输出v_O的波形。

A.客体失去对象化的形式

B.主体转化为对象物

C.主体客体化

D.客体主体化

A.客体失去对象化的形式

B.主体转化为对象物

C.主体客体化

D.客体主体化

A.光导体失效

B.显影器未工作

C.未转

D.复印纸太潮

E.墨粉用完

A.联合(集中)处理站

B.计量站或计量阀组

C.油井

D.集输管道