How do you say

They expect to complete their marathon training in three months.

..in Chinese?

他们计划在三个月内完成马拉松训练。

tā men jì huà zài sān gè yuè nèi wán chéng mǎ lā sōng xùn liàn 。

How do you say "I ordered solid wood furniture online for three months, but it hasn’t arrived yet." in Chinese?