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There are many cool inventions that make our daily lives much easier. Here are four useful ones worth knowing. These creations are all designed for our daily convenience.

The rideable suitcase
It's loved by travellers worldwide. It can be ridden like a small scooter(滑板车), so heavy bags are no longer a problem. It is usually made of light but strong materials to keep users safe during long and tiring trips.
Mopping robots
They are great helpers for busy people. They are controlled by apps easily and can clean floors by themselves with no one watching. Dirt and dust are collected well by these smart machines, even in hard-to-reach corners like under sofas.
九年级

Solar-powered (太阳能) hats
They are perfect for outdoor lovers. They get power from solar energy. So, they can protect people from the harm of strong sunlight on hot summer days. At the same time, they can also charge mobile phones when the phones run out of power.
Smart wallets
They are designed to prevent people from losing them. There is a small part inside to find where it is. Alerts(警报) are sent to owners’ phones right away if the wallets are left behind somewhere, helping people avoid unnecessary troubles.
() 1. Why is the rideable suitcase made of light but strong materials?
A. To make it look more beautiful.
B. To keep users safe on long trips.
C. To make it cheaper to produce.
D. To help it carry more things.
() 2. Which invention is a good helper for busy people?
A. Mopping robots.
B. The rideable suitcase.
C. Solar-powered hats.
D. Smart wallets.
() 3. What do the four inventions have in common?
A. They all use solar energy to work.
B. They all send alerts to users’ phones.
C. They are all made of strong materials.
D. They are all designed for daily convenience.