Perhaps you should try some spelling variations:
present challenges » current challenges, assessment challenges
challenges a » challenges 1, challenges 3, challenges 5
la present » la presente, a present, la presence
wang yang » wang yan, wang liang, wang yanling
yang yi » yang di, yang xi, yang jui
a young » _ young
ng y » ng _, g y, na y
y la » a la, _ la
choi » chi, cho

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

• If you are trying to use Boolean operators, they must be ALL CAPS: ((wang yang) OR (yang yi))ng y la present challenges a young choi ;~.
• Adding a wildcard symbol may retrieve word variants: ((wang yang) or (yang yi))ng y la present challenges a young choi ;*.