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问题 解答题

已知集合A={x|x2+x-6=0}，B={x|mx-1=0}．若B⊆A，则实数m组成的集合是______．

答案

∵A={x|x2+x-6=0}，∴A={-3，2}，

又∵B⊆A

∴当m=0时，B=∅，符合题意；

当m≠0时，集合B中的元素可表示为x=

1
m
，若
1
m
=-3，则m=-
1
3
，若
1
m
=2，则m=
1
2
；

∴实数m组成的集合是{0，

1
2
，-
1
3
}．

故答案为：{0，

1
2
，-
1
3
}．

单项选择题

电梯司机在非运行高峰期间暂时离开时，应将电梯（）。

A.打成自动状态

B.锁梯

C.交给认识的人替开电梯

D.锁梯，并悬挂“请稍候”标志牌
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阅读理解

The Life Lab Garden Classroom is a two-acre, interactive （互动的）and educational garden located at the Center for Agro-ecology（农业生态） and Sustainable Food Systems Farm on the university of California, Santa Cruz campus. People of all ages can discover ecological concepts in this hands-on, living laboratory. Learn about plants, nature, weather, organic（绿色的） gardening, life cycles.
The Garden Classroom is open to the public every day from 8 am to 6 pm. Free Admission!
The Garden Classroom offers:
Field Trips
The Garden Classroom offers guided garden-based field trips for elementary school classes in the spring and fall. Themes include food systems, soil, recycling and so on.
Summer
Camp
Each summer students explore the garden and surrounding natural areas to learn science concepts, gardening basics, crafts and cooking skills .
Workshops
A variety of garden-based workshops are offered for teachers and the public in the Garden Classroom and at school sites and conferences.
Special
Events
Life Lab offers classes for students, after-school and home school programs, teacher conferences, and private events in the Garden Classroom.
The Garden Classroom was made possible through generous contributions from The David and Lucile Packard Foundation and many other organizations and individuals.
68. The text is probably taken from            .
A. a history book               B. a hotel instruction
C . an English dictionary              D. a tourist guidebook
69. The Life Garden Classroom is a place where people        .
A. grow plants and flowers                             B. see different kinds of rare plants
C . learn about plants and living creatures   D. know about the University of California
70. Tony is in Senior 1. He is quite interested in exploring the science concepts and making crafts. Which program will he choose?
A. Field Trips       B. Summer Camp         C . Workshops       D. Special Events.
71. We can know all the following from the text except        .
A. where the Life Lab Garden Classroom lies and its exact size
B. when people can come to the Life Lab Garden Classroom
C . that people are free to visit the Life Lab Garden Classroom every year
D. that the Life Lab Garden Classroom is supported by the government.
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