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问题 解答题
已知函数f(x)=
1+
1
x
，(x＞1)
x2+1，(-1≤x≤1)
2x+3，(x＜-1)
．
（1）求f(
1
2
-1
)与f（f（1））的值；
（2）若f(a)=
3
2
，求a的值．
答案

（1）f（

1
2
-1
）=f（
2
+1）=1+
1
2
+1
=1+（
2
-1）=
2
．

而f（1）=12+1=2

所以：f（f（1））=f（2）=1+

1
2
=
3
2
．

（2）当a＞1时，f（a）=1+

1
a
=
3
2
⇒a=2；

当-1≤a≤1时，f（a）=a2+1=

3
2
⇒a=±
2
2
．

当a＜-1时，f（a）=2a+3=

3
2
⇒a=-
3
4
（舍去）．

综上：a=2或a=±

2
2
．

填空题

根据句意和首字母提示完成单词。

l. There is a big tree in front of my house, and people often rest in the cool s_____  of the tree in summer.

2. Yuan Longping is famous for his h_____  rice.

3. He g_____   from the Southwest Agricultural University in 1953.

4. Yuan Longping has d_____  himself to research.

5. Yuan Longping was h_____ with the name "Father" of Hybrid Rice.

6. China now p_____  enough rice to feed her people every year.

7. In his s_____  time, he often writes some stories.

8. It is just a cold. N_____  serious.

9. Now Professor Yuan is working on d_____  super hybrid rice.

10. The farmer goes to the f_____  twice a day.
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单项选择题

某机电安装公司承建某民用高层住宅的机电安装工程。对于建筑智能化的施工，业主选定了各系统的产品型号，与各承包方签订系统安装承包合同；施工单位在工程调试中用到的各种仪表都具备有效的合格证书；消防工程验收后，经工程移交程序，将整个工程移交给使用单位；在电气工程的安装过程中，严格按照国家交接试验和验收标准的规定进行工序交接。

在建筑智能化系统中，采用模块化信息钮和信息采集棒可实现( )巡更。

A．分线式

B．划线式

C．离线式

D．在线式
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