【单选题】听力原文:PERRY: Hi, Opal. Any ideas about what we should do for our geography project? OPAL: Hi, Perry. Yes, I'd like to do something on Wetlands. PERRY: I think that's a great idea—where do we start? OPA...
A.
water quality
B.
seasonal change
C.
saturated soil
D.
safe places
E.
quite low
F.
quite high
G.
nutrients
H.
nurseries
I.
international recognition
J.
farming activity K.extinct L.continued existence M.commercial development N.at risk (15)