哪一个液压系统作动正常刹车：（）.A.绿系统 B.黄系统 C.蓝系统 D.绿系

When Joe left university, he got a good work in a bike factory.

But after he had been worked there for some years, he decided

to have change, so he put a notice in several newspapers,

saying what experiences he had and the kind of job he would

like to have. One of the answers he accepted was from a man

was looking for a job, too. This man wrote to him, “Dear, sir,

when you get a new job, be kind enough to give your name and

address to your present boss as I have been trying to find

a position like yours for a long time.” After he reads the letter,

he suddenly realized that what he had done was real foolish.

有6个数，从小到大排列为：23、25、26、30、32、32．这组数据的平均数是______，中位数是______．

下列有关预收款的说法错误的是（）。

A.经营者可以采取预收款方式提供商品或者服务

B.经营者采取预收款方式但未按照约定提供的，应当按照消费者的要求履行约定

C.经营者采取预收款方式但未按照约定提供的，应当退回预付款

D.经营者除退回预付款外，还应当承担预付款的利息和消费者预期损失

严禁氨系统超压运行，氨储罐温度高于（）℃，要及时检查其喷淋系统自动投入。