下面是一则对话，请从所给的A—G选项中选择恰当的一项填入空格处，使对话的上下文意义完整，结构连贯；选项中有两项为多余选项。
WeChat, known as Weixin in china, is a mobile phone text and voice messaging communication service which is developed by Tencent.. In less than two years，WeChat has registered 200 million users , 71 . Up to now WeChat is already one of most popular chat applications which are used in mobile phones.
Undoubtedly, WeChat is definitely a wonderful invention that changed the world, 72 As we all known, it is so easy to use WeChat. You can register WeChat with your phone number, and add your friends Number in your contact list, then you can start your conversation by tapping the voice button,
73 . In the second place, WeChat is powerful. It can send messages of voice, video, photo and text. Various informations could be sent to your friends, from which receivers could enjoy the best pleasure. In the third place, WeChat is supported on Wi-Fi, 2G, 3G, and 4G data networks, by which you can chat with your family or friends in a brand new way by using your phone no matter when and where. But you don't need worry other things, such as basic fees.
However, as a matter of fact, 74 First, so many people immerse themselves in Wechat and waste a lot of time. In addition, some functions of the Wechat may lead to crimes. Therefore, we should make the best use of it, 75 . Only in this way, can we enjoy it better.
A. but we shouldn’t spare too much time on it.
B. It's using just like a interphone.
C. why does WeChat become so popular in such a short time?
D. and its overseas markets is rising rapidly.
E. it is a wonderful invention that changed our life style.
F. the potential dangers of WeChat to the users could not be ignored.
G．most of people use wechat instead of QQ now.