He had intended to do some physics homework during the play, but he soon _____ the play so much that he

forgot all about the homework. [ ]

A. busied himself enjoying 　　　　

B. involved himself to enjoy 　　

C. found himself enjoying　　　　　

D. convinced himself to enjoy

合同履行的基本原则是（）。

A.全面履行

B.诚实信用履行

C.及时履行

D.彻底履行