How do you say

Children participated in a lot of educational activities during the summer vacation.

..in Chinese?

孩子们在暑假期间参加了很多有益的教育活动。

hái zi men zài shǔ jià qī jiān cān jiā le hěn duō yǒu yì de jiào yù huó dòng 。

How do you say "There has been great variation in the weather in Beijing recently, with a large temperature difference between day and night; one must take care to wear adequate clothing to keep warm." in Chinese?