Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
challenges a » challenges 1, challenges 3, challenges 5
wang liang » wang yang
3 present » _ present
zhong zhi » zhang zhi, zhong tai
yang jui » yang judy, yang di, yang xi
hong ghi » hong g, hong hai
png a » png _, lng a, peg a

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((wang liang) or (yang jui))png a 3 present challenges a ((hong ghi) OR (zhong zhi)) ;~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang liang) OR (yang jui))png a 3 present challenges a ((hong ghi) OR (zhong zhi)) ;.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((wang liang) or (yang jui))png a 3 present challenges a ((hong ghi) OR (zhong zhi)) ;".
• Adding a wildcard symbol may retrieve word variants: ((wang liang) or (yang jui))png a 3 present challenges a ((hong ghi) OR (zhong zhi)) ;*.