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
hong hai » shang hai, zhong tai, dang hai
yang yi » yang di, yang xi, 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 yi))ng y 2 present challenges tan hong hai ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang yang) OR (yang yi))ng y 2 present challenges tan hong hai ;.
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang yi))ng y 2 present challenges tan hong hai ;*.