I'm George's mother.My son spent(a) good time with you during his stay in your family .You provided board(boarding) and lodging voluntarily.When he came back,we found he was stronger and taller.I'm so thankful to all of you.
I'm(I will be) very pleased if you come(came) to China.This time,we invite you
to our home .You can let Mark to(去掉TO) be an exchange(exchanged) student to visit China.
From the photo,I think Alison is a very pretty and cute girl.
原因还用解释吗?我其实也是试一下.你自己应该看明白我为什么改的