challenging
adj
ˈtʃælɪəndʒɪŋ
adj
1
difficult
in
an
interesting
or
enjoyable
way
富于挑战性的; 困难而有趣的; 需充分发挥能力的
Teaching
young
children
is
a
challenging
and
rewarding
job.
教育儿童是一项具有挑战性和有意义的工作。
a
challenging
problem
具有挑战性的难题