在激素与恶性肿瘤发生的研究中，目前认为可能具有致癌作用的激素是（）。
A.甲状腺素
B.孕激素
C.前列腺素
D.雌激素
E.肾上腺皮质激素
参考答案：D
A 4-year-old girl is admitted to the hospital to rule out leukemi
a. Which of the following would be the best room assignmentA. With a 4-year-old girl who has rheumatoid arthritis.B. With a 5-year-old boy who is having a tonsillectomy.C. With a 4-year-old girl who has leukemia.D. Alone in a private room.
导致合同终止的原因主要有( )。
A．合同解除
B．债务相互抵销
C．债务人依法将标的物提存
D．合同转止
E．债权债务同归于一人
