用英语学手机英语口语：手机流量可以expire和roll over是什么意思？
如果问你一句：What happens to your smartphone data if it is unused at the end of the month?
你怎么用英语回答？
1) URead：在“英语语言环境”中体验英语，学习英语：
Here’s what happen to your unused mobile data quota.
In the US and in most other countries when you pay for data each month, you lose what you don’t use with most carriers. This is a major source of annoyance for just about everyone who has a mobile phone with a data plan. If you pay for something and don’t use it all, you should get to keep that data. AT&T and other carriers in the US do allow you to roll over unused data to the coming month.
The catch(the rule)is that your extra data expires if you don’t use it. That’s not how it works with a carrier in New Zealand called 2degrees
2) UTalk, 自己跟自己说英语：
如果我们在上面的“英语语言环境”中认真“体验英语”的话，就会发现：我们从中学会了“哦，手机流量滚存或清零”用英语原来是这么说的。
1. 流量滚存：
If you pay for data and don’t use it all, you should get to keep that data. AT&T and other carriers in the US do allow you to roll over unused data to the coming month.
roll over unused data to the coming month就是“用不完的流量可以滚存到下月使用”。
Well my unused data/extra data will expire if I don't use it all/and I can't keep it.
把这句英语反复发生读几遍哟！
What is Data will expire?
也可以说：When we say the data will expire,we can also say the data disappears, or I will lose the unused data,
OR, my data allowance resets.
不过，“一义多说”确实是让外语学习者头痛的事，英语如此，中文也如此。所以，多下功夫记忆吧。
,
