Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
challenges tan » challenges call, challenges time, challenges 1
wang yang » wang yan, wang liang, wang yanling
2 present » _ present, 3 present
tan zhong » tan hong, tan kong, can hong
zhong tai » hong tan, hong hai, zhong zhi
yang xi » yang di, yang yi, yang jui
ng y » ng _, g y, na y

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((wang yang) or (yang xi))ng y 2 present challenges tan zhong tai ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang yang) OR (yang xi))ng y 2 present challenges tan zhong tai ;.
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang xi))ng y 2 present challenges tan zhong tai ;*.