一道SAT语法题,这里怎么判断until是什么词性?Untilrelativelyrecentlyhumanswerethoughttobeuniquelyself-aware,scientistsnowknowthatmostchimpanzesandorangutanscanrecognizetheirownreflections.A:scientistsnowknowB:but

Question

一道SAT语法题,这里怎么判断until 是什么词性?
Until relatively recently humans were thought to be uniquely self-aware,scientists now know that most chimpanzes and orangutans can recognize their own reflections.
A:scientists now know
B:but scientists now know
C:but scientists who now know
D:however,scientists now know
E:but with scientists now knowing
B
为什么until 在这里不能当连词啊

Answer 1

until后面的relatively 的意思是相对的,比较地,后面scientists now know that中的now其实已经给出了答案,就只能是B了.