保险合同的主体变更是指保险合同的当事人或关系人的变更，即保险合同的( )。 A．转

Now, most people have watches. As we know, Switzerland（瑞士） is famous for its watches. ___ , the watch was not _ in this country. It was the British who did. Many years ago, an Englishman traveled to Italy and on his way he went     a small town in Switzerland. This Englishman traveled in a carriage（马车） inside which there was a carriage watch. This was the __ kind of watch. A blacksmith’s（铁匠） assistant hoped to see the watch. He __ what it was. __ he asked the Englishman about it. “ It is a carriage watch,” said the Englishman. “ This machine can tell the ___ but now it isn’t working.”

At once the blacksmith’s assistant decided to try to __ it. So the traveler handed him the watch. He was very __. So it was not surprising that he was __ in showing it right. He even remembered how it was made. As soon as the traveler had gone, he made a watch of exactly the same kind.

So the watch-making was started in Switzerland. Today Swiss watches are sold all over the world.

对“a，b，c是不全相等的正数”，给出如下判断：

①(a－b)²＋(b－c)²＋(c－a)²≠0；②a＞b与a＜b及a＝b中至少有一个成立；

③a≠c，b≠c，a≠b不能同时成立，其中判断正确的个数是（    ）

A．0

B．1

C．2

D．3

隙卡沟的正确宽度为

A．0.5～0.6mm
B．0.6～0.7mm
C．0.7～0.8mm
D．0.8～0.9mm
E．0.9～1.0mm

为什么通常可根据水的电导率和氯化物含量来来表征水中含盐量？

路堤横向排水沟及路堤边坡上的排水沟均应在路堤处于（）后方可施工。

A、填筑

B、竣工

C、沉降

D、稳定