First the cover that can be the first letter I've ever received from China. I received it from a swap previous to Postcrossing era.
The other 2 are more recent, already 2009.
Although I mainly collect european countries only I must say chinese stamps are very interesting. Very colorful and traditional. And another advantage: they are real stamps, not those awful sticker stamps european and north american post offices insist on issuying! Keep it that way, please!