Zhōngxiào shì shàngxiào hé shàoxiào zhījiān de jūnxián.
Lieutenant colonel is the rank between colonel and major.
Tips
memory
中 (middle) + 校 (school/field officer) = middle-rank field officer. The system is 少校 (major) < 中校 (lt. colonel) < 上校 (colonel), using 少/中/上 for junior/middle/senior.