查看材料A.Ashorterlengthofcourse.B.AnewpracticecalledFIELD.C.Personalcontactwiththeclean.D

查看材料

A.A shorter length of course.

B.A new practice called FIELD.

C.Personal contact with the clean.

D.More opportunities of case study.

请帮忙给出正确答案和分析，谢谢！