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pyrethrin

/paɪˈriːθrɪn/ /pɪˈriːθrɪn/

Meanings
noun

除虫菊酯，除虫菊精。

Any of a number of naturally occurring insecticides extracted from the pyrethrum plant; unusual in having a cyclopropane ring.

Examples :

"The gardener sprayed pyrethrin on the roses to kill the aphids. "
园丁在玫瑰花上喷洒了除虫菊酯，以杀死蚜虫。
compound substance chemistry agriculture insect plant science biology nature environment

Related Words

Illustration naturally

naturally adverb

/ˈnætʃ(ə)ɹəli/

自然地，天生地，顺理成章地

"Although he was unused to the situation, he tried to act naturally."

尽管他不习惯这种情况，但他还是努力表现得很自然。

Illustration sprayed

sprayed verb

/spɹeɪd/

喷洒，喷射.

"The firemen sprayed the house."

消防员向房子喷水。

Illustration occurring

occurring verb

/əˈkɜːɹɪŋ/ /əˈkɝɪŋ/

发生，出现。

"The liftoff will occur in exactly twelve seconds."

起飞将在精确的十二秒后发生。

Illustration gardener

gardener noun

/ˈɡɑːdnə/ /ˈɡɑɹdnɚ/

园丁，花匠。

""Ponder the fact that God has made you a gardener, to root out vice and to plant virtue." — St. Catherine of Siena"

想想吧，上帝让你成为了一位园丁，让你铲除恶习，播种美德。

Illustration having

having verb

/ˈhævɪŋ/

拥有，具有。

"I have a house and a car."

我拥有一栋房子和一辆汽车。

Illustration cyclopropane

cyclopropane noun

/ˌsaɪkloʊˈproʊpeɪn/

环丙烷

"Because of its anesthetic properties, cyclopropane was once used in hospitals to help patients during surgery, but its flammability made it a risky choice. "

由于环丙烷具有麻醉特性，曾经被医院用于帮助病人进行手术，但由于其易燃性，使得它成为一种具有风险的选择。

Illustration extracted

extracted verb

/ɛkˈstɹæktɪd/

提取，拔出。

"to extract a tooth from its socket, a stump from the earth, or a splinter from the finger"

把牙齿从牙槽里拔出，把树桩从土里挖出，或者把刺从手指里挑出。

Illustration pyrethrum

pyrethrum noun

/paɪˈɹiθɹəm/

除虫菊

"My grandmother grows pyrethrum in her garden for its beautiful flowers and natural insecticidal properties. "

我的奶奶在她的花园里种除虫菊，既因为它的花朵美丽，也因为它有天然的杀虫功效。

Illustration insecticides

insecticides noun

/ɪnˈsɛktɪsaɪdz/

杀虫剂，杀虫药。

"Farmers use insecticides to protect their crops from being eaten by bugs. "

农民使用杀虫剂来保护他们的庄稼，防止被虫子吃掉。

Illustration unusual

unusual noun

/ʌnˈjuːʒuəl/

不寻常的事物，异常现象。

"The student's sudden absence was an unusual for her. "

这名学生突然缺席，对她来说是个反常现象。

Illustration number

number noun

/ˈnʌmbə/ /ˈnʌmbɚ/ /ˈnʌmə/ /ˈnʌmɚ/

数字，号码

"Zero, one, −1, 2.5, and pi are all numbers."

零、一、负一、二点五和π都是数字。

Illustration aphids

aphids noun

/ˈeɪfɪdz/

蚜虫，腻虫

"The roses in the garden are covered in tiny green aphids that are sucking the sap from the leaves. "

花园里的玫瑰花上爬满了绿色的小蚜虫，它们正吸食叶子的汁液。