Definition: difficult, in a way that tests your ability or determination Level: B1
这对我们所有人来说都是一段充满挑战的时期。
This has been a ___challenging time for us all.
像骑士一样，我们骑马穿越全国，寻找冒险和富有挑战性的活动。
Like cavaliers we ride across the country looking for adventures and ___challenging activities.
解决谜题可能非常有挑战性。
Solving puzzles can be very ___challenging.
