变压器是将一种交流电转换成同频率的另一种（）的静止设备。A、直流电B、交流电C、大电

短文改错。

     假定英语课上老师要求同桌之间交换修改作文，请你修改你同桌写的以下作文。文

中共有10处语言错误，每句中最多有两处。每处错误涉及一个单词的增加、删除或修改。

增加：在缺词处加一个漏字符号(∧)，并在其下面写出该加的词。

删除：把多余的词用斜线(/)划掉。

修改：在错的词下划一横线，并在该词下面写出修改后的词。

注意：

1.每处错误及其修改均仅限一词；

2. 只允许修改10处，多者(从第11处起)不计分。

     My parents and I went to the park last Sunday. There were lots of visitors stand in front of the

ticket window. We waited a long time and buy three tickets. In the Tiger Mountain of the park, I

was too eager to see the fierce frightened animals that I quickened my steps through the crowd.

Unfortunate, I got separated from my parents. I had hard time looking for them, and I had no luck.

Wandering in the park, I felt alone without any companions. Worse still, I had no money, so I had

to walk to home, covering as much as 5 kilometer.

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请用不超过150字的篇幅，概括出给定材料所反映的主要问题。

什么是效能监察的“三评四警”活动？

肠瘘病人术后应采取的饮食为( )。

A．低脂

B．高蛋白

C．适量蛋白质

D．高碳水化合物

E．低渣

For（1） service, we need a virtual-circuit subnet. Let us see how that works. The idea behind virtual circuits is to avoid having to choose a new （2） for every packet sent. Instead,when a connection is established, a route from the （3）machine to the destination machine ischosen as part of the connection setup and stored in tables inside the（4）That route is used forall traffic flowing over the connection, exactly the same way that the telephone system works.When the connection is released, the virtual circuit is also terminated. With connection-orientedservice, each packet carries an （5）telling which virtual circuit it belongs to.

（1）是（）

A.connectionless

B.connection-oriented

C.datagram

D.telegram