在雅思口语里，an important invention 一提起来我们就想到手机...但雅思考官听了千万遍手机难免反感。或许换个思路看看!微波炉对于现代生活节奏快速的青年人，尤其是不会做饭的人来说，简直是最伟大的发明，吃不完的各种leftover或者frozen dinner，在微波炉里一转，就又是一餐！除此之外，还可以用来爆popcorn，煮instant noodles！简直是生活必备！但是有人会argue说，微波炉出来的东西不是很健康，但是whatever啦，关于它如何方便简直太好说了，所以完全可以作为雅思口语important invention的素材！
In my opinion, microwaves are an important invention in our daily life. Basically every family has this household appliance in their kitchen, and they have made our life a lot easier. I mean, it's a convenient way to cook food and reheat leftovers. So they are a great helper for busy people with a tight schedule or short lunch break.
For example, in the morning, if we want to drink a cup of hot milk, we don't need to turn on the stove anymore, we just need to put the milk in the microwave, and wait for about 30 seconds, then ta-da, there's hot milk. And when students are preparing for the exams and too busy to have a decent meal, we could always put instant noodles or frozen dinner into the microwave, and soon, dinner will be ready.
Besides, my mom loves to use it to cook potatoes for me. It's super simple, we just need to wrap the unpeeled potato with wet tissues, and put it in the microwave. After about 10 minutes, the healthy, palatable 'baked' potato could be served on the table. And for someone who doesn't know how to cook, microwaves can be a lifesaver. If you read the instruction manual carefully, we can even cook fish, soup, chicken and things like that.
And for me, I used to make popcorn with the microwave before I started to watch a movie at home. It's just super convenient.
So it's fair to say, it's really an important invention.
Appliance = a machine that is designed to do a particular thing in the home, such as preparing food, heating or cleaning 例如：
electrical/ household appliances
They sell a wide range of domestic appliances—washing machines, dishwashers and so on.
Leftovers = food that has not been eaten at the end of a meal
Break = a short period of time when you stop what you are doing and rest, eat, etc. 例如：
Let's take a break.
She worked all day without a break.
Stove = a large piece of equipment for cooking food, containing an oven and gas or electric rings on top 例如：
She put a pan of water on the stove.
Most people don't want to spend hours slaving over a hot stove (= cooking).
Ta-da = an exclamation to substitute a lot of words, especially when excited, happy or surprised, and usually the final proclamation when something is finished. 例如：
Hey, look what we got today! Tada!!
Decent = of a good enough standard or quality 例如：
a decent meal/ job/ place to live
I need a decent night's sleep.
Lifesaver = a thing that helps somebody in a difficult situation; something that saves somebody's life 例如：
The new drug is a potential lifesaver.
Manual = a book that tells you how to do or operate something, especially one that comes with a machine, etc. when you buy it 例如：
Why don't you read the manual?
The instruction manual completely defeated me. = you cannot understand it