How do you say

Train tickets are now on sale three weeks in advance at a 70% discount.

..in Chinese?

火车票七折已经可以买到三周后的票了。

huǒ chē piào qī zhé yǐ jīng kě yǐ mǎi dào sān zhōu hòu de piào le 。

How do you say "He expects to fly to London in three months." in Chinese?