阅读下列短文，从每题所给的A、B、C和D四个选项中，选出最佳选项。
A
Smart Things on Their Way
Google Clips
Google Clips is designed to be put somewhere in a room to take pictures by itself. It can also be attached to an object or a person's clothing.
Google says Machine Learning helps the camera choose the best times and situations for taking pictures and videos. Interested buyers can join a waiting list for the product to be on the market.
GoPro Hero
GoPro also uses Machine Learning to power its QuikStories characteristic. This tool takes existing photos and videos and automatically creates a finished video piece, complete with music and effects.
Snap Sunglasses
Messaging app Snapchat sells a pair of sunglasses with a built-in camera that can record short videos with the push of a button. Snap Inc. says the product is designed to “catch the moment, without taking you out of it.”
The glasses can record short video clips that can be shared with Snapchat users. Snap Inc. has started selling its sunglasses online.
Apple iPhone X
Apple's new iPhone X has a new Face ID system that it says will unlock the phone just by having the user look at it. This replaces the Touch ID on previous ones that used a fingerprint to unlock the phone.
Apple says the system works by projecting more than 30,000 dots on the face to create a kind of map. Apple says its facial recognition is even safe enough to allow payments through its Apple Pay service.
21.What do Google Clips and GoPro Hero have in common?
A.Both can only be used indoors.
B.Both can be bought online now.
C.Both are operated with the help of Machine Learning.
D.Both can create a video piece automatically.
22.What is special about Snap Sunglasses?
A.The glasses have a camera that can be attached to an object.
B.The glasses can cover the person who takes the picture.
C.The glasses can store long videos and share them online.
D.The glasses have music and effects.
23.What can we know about Apple iPhone X from the text?
A.It can recognize the user’s face.
B.It can take a picture of the user’s face.
C.It can be unlocked by a fingerprint.
D.It is absolutely safe.
