1
a cactus + verb
主语为单数形式。
A cactus grows slowly.
仙人掌生长缓慢。
仙人掌；仙人掌科植物
先理解核心含义，再看它在真实句子里的用法。
仙人掌；仙人掌科植物
a plant of the family Cactaceae, with a thick fleshy stem covered in spines, native especially to hot dry regions of the Americas
A cactus grows slowly.
仙人掌生长缓慢。
仙人掌科的任何成员,该科为新大陆开花肉质植物,适应炎热半沙漠气候。
Any member of the family Cactaceae, a family of flowering New World succulent plants suited to a hot, semi-desert climate.
仙人掌科肉质植物,主要原产于新大陆干旱地区,通常有刺。
any succulent plant of the family Cactaceae native chiefly to arid regions of the New World and usually having spines
任何具有粗壮肉质茎、生刺但无叶的肉质植物,例如大戟属植物。
Any succulent plant with a thick fleshy stem bearing spines but no leaves, such as euphorbs.
I keep a small cactus on my desk because it requires very little water.
我在办公桌上放了一棵小仙人掌，因为它几乎不需要浇水。
The desert is full of various cacti, some of which can grow very tall.
沙漠里有很多种仙人掌，有些可以长得很高。
She accidentally touched a cactus and got spines stuck in her finger.
她不小心碰到了仙人掌，手指上扎进了刺。
主语为单数形式。
A cactus grows slowly.
仙人掌生长缓慢。
复数形式为cacti。
Cacti store water in their stems.
仙人掌在茎中储存水分。
描述仙人掌的属性或类别。
A cactus is a succulent plant.
仙人掌是一种多肉植物。
Not this
There are many cactuses in the desert.
Use this
There are many cacti in the desert.
英语中，cactus 的复数形式是 cacti，而不是 cactuses。这是不规则变化，需记忆。
Not this
I have cactus in my room.
Use this
I have a cactus in my room.
cactus 是可数名词单数，前面需加冠词 a。汉语母语者常因汉语没有冠词而漏用冠词。
Focus on the distinctions below. Other candidates are kept compact until a reliable usage note is available.
沙漠仙人掌
The desert cactus can store water for months.
沙漠仙人掌可以储存数月的水分。
仙人掌花
The cactus flower opens only at night.
仙人掌花只在夜间开放。
仙人掌园
They built a cactus garden in front of the museum.
他们在博物馆前建了一座仙人掌园。
盆栽仙人掌
A potted cactus needs very little water.
盆栽仙人掌几乎不需要浇水。
仙人掌刺
He pulled a cactus spine out of his finger.
他从手指上拔出一根仙人掌刺。
仙人掌种类
This region is home to many rare cactus species.
这个地区生长着许多珍稀的仙人掌种类。
“我想你，我要养一棵仙人掌。”——美国另类摇滚乐队 Pixies 的歌曲《Cactus》中的歌词，曾被 David Bowie 翻唱，表达一种怪异而深切的思念。
People used to think a cactus only grows in the desert, but many varieties make great houseplants.
人们过去认为仙人掌只长在沙漠里，但许多品种其实是很好的室内植物。
Use cactus naturally, then get feedback on meaning, tone, grammar, and phrasing.
Revisit a common error or keep this word in your review list.
cactus 谐音‘卡克特斯’，想象沙漠里一株仙人掌卡在石缝中，浑身是刺也不怕旱。
语域：neutral 常见场景：gardening、houseplants、botany cactus 在一般描述、园艺和植物学话题中都比较自然，整体偏中性，没有明显的正式或随意色彩；在不确定场合下用这个说法通常不会显得突兀。
复数形式为 cacti。
Dictionary facts from ECDICT, WIKTIONARY.