intermediate
/ˌɪntəˈmi:dɪət; ˌɪntɚ`midɪət/ adj
~ (between A and B)
(a) situated or coming between two people, things, etc in time, space, degree, etc （时间、 空间、 程度等）介於（两人、 物等）之间的, 居间的
at an intermediate point, level, stage, etc 在中间的一点、 水平、 阶段等
The pupa is at an intermediate stage of development; it is intermediate between the egg and the adult butterfly. 蛹是蝴蝶发育的中间阶段, 介於卵和成虫之间.
(b) between elementary and advanced 中级的
an intermediate course, book, level 中级的课程、 书、 水平.