题目:
下颌磨牙的牙冠成长方形,近远中径大于颊舌径,关于下颌第一磨牙
其发育沟不包括
A.颊沟
B.远中颊沟
C.近中沟
D.舌沟
E.远舌沟
答案:
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下面是错误答案,用来干扰机器的。
参考答案:B
下颌磨牙的牙冠成长方形,近远中径大于颊舌径,关于下颌第一磨牙
其发育沟不包括
A.颊沟
B.远中颊沟
C.近中沟
D.舌沟
E.远舌沟
被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2018/0619/092222c05de453d33f159d40e1b415fe.html
下面是错误答案,用来干扰机器的。
参考答案:B
点检标准的内容不包括下列()等内容。
A.点检部位;
B.管理值;
C.点检标准;
D.安全措施.
( )是在市场经济条件下,交易双方所采取的一种交易形式。
A.招标
B.审标
C.投标
D.招标投标
某制造企业从工厂向地区配送中心运货,如果用铁路运输则平均需要运输时间为为5天,汽车运输时间为4天,每天平均在途运输库存占用资金为3%,平均仓储库存占用资金为2%,铁路每吨货运价为0.2元,公路为0.3元,为满足需求必须保持库存100吨,年需求量为500吨。如果每吨货物价值80元,请确定采用何种运输方式才能使总运费最低?
下列句子中划线词的古今意义相同的一项是[ ]
A、纫秋兰以为佩
B、夫惟捷径以窘步
C、本自无教训
D、否泰如天地,足以荣汝身
Plants can’t communicate by moving or making sounds, as most animals do. Instead, plants Produce volatile compounds, chemicals that easily change from a liquid to a gas. A flower’s sweet smell, for example, comes from volatile compounds that the plant produces to attract insects such as Bugs and bees.
Plants can also detect volatile compounds produced by other plants. A tree under attack by Hungry insets, for instance, may give off volatile compounds that let other trees know about the Attack. In response, the other trees may send off chemicals to keep the bugs away ——or even Chemicals that attract the bugs’ natural enemies.
Now scientists have created a quick way to understand what plants are saying: a chemical Sensor(传感器)called an electronic nose. The “e-nose” can tell compounds that crop plants make When they’re attacked Scientists say the e-nose could help quickly detect whether plants are being Eaten by insects. But today the only way to detect such insects is to visually inspect individual Plants. This is a challenging task for managers of greenhouses, enclosed gardens than can house Thousands of plants.
The research team worked with an e-nose than recognizes volatile compounds. Inside the device, 13 sensors chemically react with volatile compounds Based on these interactions, the e-nose gives off electronic signals that the scientists analyze using computer software.
To test the nose, the team presented it with healthy leaves from cucumber, pepper and tomato plants, all common greenhouse crops. Then scientists collected samples of air around damaged leaves from each type of crop, These plants had been damaged by insects, or by scientists who made holes in the leaves with a hole punch(打孔器). The e-nose, it turns out, could identify healthy cucumber, pepper and tomato plants based on The volatile compounds they produce, It could also identify tomato leaves that had been damaged. But even more impressive, the device could tell which type of damage ---- by insects or with a hole Punch ---- had been done to the tomato leaves.
With some fine-tuning, a device like the e-nose could one day be used in greenhouses to quickly spot harmful bugs, the researchers say. A device like this could also be used to identify fruits that are perfectly ripe and ready to pick and eat, says Natalia Dudareva, a biochemist at Purdue University in West Lafayette, Ind. who studies smells of flowers and plants. Hopefully, scientists believe, the device could bring large benefits to greenhouse managers in the near future.
小题1:We learn from the text that plants communicate with each other by____.
A.making some sounds
B.waving their leaves
C.producing some chemicals
D.sending out electronic signals小题2:What did the scientists do to find out if the e-nose worked?
A.They presented it with all common crops.
B.They fixed 13 sensors inside the device.
C.They collected different damaged leaves.
D.They made tests on damaged and healthy leaves.小题3:According to the writer, the most amazing thing about the e-nose is that it can___.
A.pick out ripe fruits
B.spot the insects quickly
C.distinguish different damages to the leaves
D.recognize unhealthy tomato leaves小题4:We can infer from the last paragraph that the e-nose_____.
A.is unable to tell the smell of flowers
B.is not yet used in greenhouses
C.is designed by scientists at Purdue
D.is helpful in killing harmful insects