接触直接入口食品人员的工作服应（）更换后清洗、消毒。 A.每天 B.每2天 C.每3

编写如下窗体事件过程：
Priate Sub Form_MouseDown(Button As Integer,Shift As Integer,X As Single,Y As Single)
If Shift=6 And Button=2 Then
MsgBox"Hello"
End If
End Sub
程序运行后，为了在窗体上消息框中输出“Hello”信息，在窗体上应执行的操作是______。

A．同时按下Shift键和鼠标左键
B．同时按下Shift键和鼠标右键
C．同时按下Ctrl、Alt键和鼠标左键
D．同时按下Ctrl、Alt键和鼠标右键

木糖醇是一种新型的甜味剂，它具有甜味足，溶解性好，防龋齿，适合糖尿病患者的食用。它是一种白色粉末状的结晶，结构简式为：

下列有关木糖醇的叙述中正确的是（   ）

A．木糖醇是—种单糖，不能发生水解反应

B．木糖醇在一定条件下能发生消去反应

C．木糖醇难溶于水，能发生酯化反应

D．1mol木糖醇与足量钠反应最多可产生5molH₂

My Garden

-----by Nelson Mandela

In early 1977, the authorities (当局) announced the physical labour and arranged some kind of work for us to do in the courtyard. The free time also allowed me to hunt what became two of my favorite hobbies in Robben Island---gardening and tennis.

To survive in prison, one must develop ways to take satisfaction in one's daily life. One can feel fulfilled (充实) by washing one's clothes so that they are particularly clean. Just as one takes pride in important tasks outside of prison, one can find the same pride in doing small things inside prison. Almost from the beginning of my sentence on Robben Island, I asked the authorities for permission to start a garden in the courtyard. For years, they refused without offering a reason. But finally they gave in, and we were able to cut out a small garden in the prison.

The soil in the courtyard was dry and rocky. In order to start my garden, I had to remove a great many rocks to allow the plant room to grow.

The authorities supplied me with seeds. At first, I planned tomatoes and onions, because these plants did not require rich earth or constant care. The early harvests were poor, but they soon improved.

I began to order books on gardening. I studied different gardening techniques and types of fertilizers (肥料). For a time, I tried to grow peanuts, and used different soils and fertilizers, but finally I gave up. It was one of my few failures.

A garden was one of the few things in prison that one could control. The processes of planting a seed, watching it grow, taking care of it and then harvesting it offered a simple but long-lasting satisfaction. The sense of being the owner of the small patch of earth offered a small taste of freedom.

小题1:Mandela's hobbies on Robben Island were ____.

A．hunting and physical labour

B．gardening and tennis

C．washing his clothes

D．gardening techniques and types of fertilizers小题2:When did Mandela ask the prison authorities for the permission to start a small garden?

A．Soon after 1997.

B．Some time in early 1977.

C．Almost as soon as he went to prison there.

D．Long after he went to prison there.小题3:Why did Mandela wash his clothes especially clean although he was in prison?

A．To show he could do it as well as others.

B．To get some sense of pride and satisfaction from it.

C．To show others that he preferred to be clean.

D．To gain the authorities' permission to start a garden.小题4:Hard as he tried, he failed ____ at last.

A．to get a sense of satisfaction and freedom

B．to grow tomatoes and onions

C．to grow peanuts

D．to get the same pride inside prison.

凹陷状痕迹的凸凹象与形成痕迹的工具的凸凹象相反（）。

A、错误

B、正确

C、不完整

D、正确、完善

冷凝压力和温度取决与（）的温度。

A.压缩机

B.冷冻机油

C.冷却水

D.制冷剂