根据《合同法》的规定，出现下列( )情形的，导致合同终止。

A．合同解除
B．履行期限届满，当事人未履行合同义务
C．订立合同后，一方当事人发生分立
D．一方经对方同意，将合同的债权债务概括转让

She _____ his number in the phone book to make sure that she had got it right.[ ]

A. looked for

B. looked up

C. looked after

D. looked like