Perhaps you should try some spelling variations:
teaching china » teaching doing
class teaching » class teachers, class teacher, classroom teaching
china roberto » chang roberto, change roberto, asia roberto
sein time » sein die, sein eine, mean time
roberto n » robert _, robert e, robert j
tan ying » ran ying, tan yang, tan yong
fan ying » fan xing, ran ying, jin ying
den time » down time, open time, mean time

You may be able to get more results by adjusting your search query.

• If you are trying to use Boolean operators, they must be ALL CAPS: ((tan ying) OR (fan ying)) ((sein time) OR (den time)) class teaching china roberto n ;~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tan ying) or (fan ying)) ((sein time) OR (den time)) class teaching china roberto n ;~".
• Adding a wildcard symbol may retrieve word variants: ((tan ying) or (fan ying)) ((sein time) OR (den time)) class teaching china roberto n ;*.