题干

植物体没有专门的脂肪组织,但在花生、大豆、蓖麻等植物的种子中富含脂肪.某兴趣小组想通过实验检测植物根尖细胞中是否也含有脂肪.请完善下列实验方案.

(1)材料用具:

新鲜洋葱根尖、苏丹Ⅲ染液、体积分数为50%的酒精溶液、蒸馏水、____ ____ 、____ 、刀片、培养皿、镊子、滴管等.

(2)方法步骤:

①选取新鲜的洋葱根尖并作徒手切片;选取2~3片最薄切片放置在载玻片的中央;

____ ,2~3min后滴加体积分数为50%的酒精溶液,洗去浮色;

③在切片上滴1﹣2滴蒸馏水,盖上盖玻片,制成临时装片;

____ .

(3)预期结果与相应结论:

____ ;

____ .

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阅读理解

When you're not at home, many worries may start to crowd your mind. Did I turn the coffee maker off?

Did I lock the door? With a smart home, you can keep all of these worries off.

A smart home is a home with a communication network. This network connects devices (装置), such as lights and TV sets, and allows them to be controlled from far away through electrical wiring, mobile phone communication or WiFi over the Internet.

More and more people may start to consider owning a smart home, because it makes life much more convenient. It can help keep your room at a certain temperature. It can record what happens inside the home and send the video to your phone. When you are on vacation abroad, you can use a smart home controller to switch on or off the electricity when necessary. Some smart homes can receive a visitor, allowing him to come in and offering him a drink. They can even feed the cat and water the plants.

Besides, smart homes are easy to fix. Most smart home technology and devices are wireless and can be set up with a minimum of tools, using only the guiding information. When a problem appears, you can deal with it yourself without paying a professional.

However, for home-users, the smart home technology is far from perfect. It can be rather expensive to own the technology and the devices. Also, because the smart home system (系统) allows its owner to get home information from anywhere, it leaves the home easy to be attacked by hackers (黑客),who may secretly use or change the information in the system.

Now, many scientists are excited at the future of smart home technology. Imagine being able to get fashion advice from your mirror, or receive food shopping suggestions from your refrigerator, while there are others who worry that those smart devices will make people lazier and lonelier. Whatever it is, one thing is for sure — smart home technology will change the way we live and work.