已知三角形的三条中位线的长分别是3、4、6，则这个三角形的周长为（　　）

A．6.5

B．13

C．24

D．26

In a typical audiolingual lesson the procedures are followed in the order of （）

A. imitation, recognition and repetition, pattern drills and follow-up activities

B. recognition, imitation and pattern drills, repetition and follow-up activities

C. imitation, recognition, pattern drills and repetition, and follow-up activities

D. recognition, imitation and repetition, pattern drills and follow-up activities