Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
challenges xia » challenges 1, challenges 3, challenges 5
3 present » _ present
xia shang » xiao zhang, xia fang, jia zhang
shang hai » shang kai, dang hai, chang ha
yang xi » yang di, yang jui
yang yi » yang di, yang jui
png a » png _, peg a
lng a » lng _, leg a, lpg a
wang » wing, wan, lang

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

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