unchallenging
/ˌʌnˈtʃælɪndʒɪŋ/adjective
1- (of a task or situation) not testing one's abilities（任务, 形势）无挑战性的：
my job was unchallenging.
我的工作毫无挑战性。
1.1
- not threatening someone's position无威胁性的：
his voice was gentle and unchallenging.
他的语调柔和, 毫无威胁之意。