5. I quite enjoy practising shadow boxing.
我非常喜欢练习太极拳。
还能这样说：
Shadow boxing is my favorite.
I like shadow boxing.
应用解析：
the shadows of old age 老态;
the shadow of a name 虚名;
live in the shadow 隐姓埋名;
be afraid of one's own shadow 草木皆兵，胆小到极点
6. TaiChiChuan is a form of martial arts.
太极拳是武术的一种形式。
还能这样说：
TaiChiChuan is a form of Chinese martial art.
Martial arts contains TaiChiChuan.
应用解析：
fill out a form 填表格;
take the form of 采取……的形式;
standardize a form 使一种形式标准化;
form from 由……组成，用……构成;
form after 按照……构成
7. Do you know if there are some relations between TaiChiChuan and Qigong?
你知道太极拳和气功之间有什么联系吗?
还能这样说：
Does TaiChiChuan have anything to do with Qigong?
Is there any relationship between TaiChiChuan and Qigong?
应用解析：
have relation to 和……有关系;
with relaton to 关于……;就……而论;
make relation to 提及;读到;
relation by marriage 姻亲，裙带关系
8. I did fencing occasionally while I was at college.
我在大学时偶尔玩玩击剑。
还能这样说：
I did a bit of fencing while I was at university.
During my college life, I did fencing once a while.
应用解析：
fence round the point 避开问题的要点;
fence againt 防御……
off the fence 犹豫不决;
on sb.'s fence 帮助某人