Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
wang yang » wang yan, wang liang, wang yanling
a present » _ present, 3 present, 2 present
yang xi » yang di, yang yi, yang jui
ma hong » a hong, kia hong, tan hong
m hong » _ hong, a hong, 2 hong
ng y » ng _, g y, na y
y a » y la

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 a present challenges ((m hong) OR (ma hong)) hai ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang yang) OR (yang xi))ng y a present challenges ((m hong) OR (ma hong)) hai ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang yang) or (yang xi))ng y a present challenges ((m hong) OR (ma hong)) hai ;".
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang xi))ng y a present challenges ((m hong) OR (ma hong)) hai ;*.