科学家发现某些原子具有放射性，即原子能自动地放射出一些固定的粒子．据此推断，当一种元素的原子经过放射变化后，结果变成了另一种元素的原子．它一定是放射了（   ）

下图为我国某地河流封冻日数等值线图，据图回答：

【小题1】图中A地的数值可能为

A．130

B．140

C．160

D．170

【小题2】关于图中B河流水文特征的叙述，不正确的是

By the time I got back to school, the bell had rung.直到我回到学校，铃已经响了。

____直到……时候

指从过去某一点到从句所示的时间为止的一段时间。如：

By the time we got to his house, he had finished supper.

在我们到达他就已经吃完了晚饭。

下列能源中，属于可再生能源的是（  ）

      Computers can help many workers. They can also help thieves.
      There was one thief who worked in a bank of the United States. He paid for everything he needed by check (支票). Then he told the computer not to take any money from his account for the checks he wrote. The bank's computer did what he said. And it did not take any money from his bank account. One day the computer broke down. People had to do the computer's work. They soon found out what was happening.
      Another thief, who worked for a bank saw people filling in deposit forms (存款单). Many of these people did not know their account numbers, so they wrote only their names on the forms. They left empty places for their account numbers. The thief wrote his own account number in this place. When the computer read these forms it looked only at the account numbers. It did not look at the customers' names. It paid the money on these deposit forms into the thief's account .                           
       Then there was the bank worker who told the bank computer to take ten cents off every customer's account each month and put it into his own account. For a long time the bank's customers did not notice that they were losing ten cents every month. But then someone did notice and told the bank. That was the end of that little game!