How do you say

He had been training assiduously for the coming marathon, the past three months.

..in Chinese?

他在过去三个月里一直在刻苦训练,为即将到来的马拉松比赛做准备。

tā zài guò qù sān gè yuè lǐ yì zhí zài kè kǔ xùn liàn , wèi jí jiāng dào lái de mǎ lā sōng bǐ sài zuò zhǔn bèi 。

How do you say "I bought a comfortable bed in a furniture store." in Chinese?