unnatural/ ^n'nætʃrəl /

1.adjective
(not normal) 反常的

2.adjective
(not sincere) 做作的

it is not unnatural that...
…是很正常的
it is unnatural to keep the sexes apart
将两性分开是不合人情的
it would be unnatural for two people to agree all the time
要两个人总是意见一致是不正常的