构成思想品德的四个基本要素是知、情、意和______。
参考答案：行
患者，女性，43岁，风湿性心脏病史10余年，二尖瓣狭窄，心功能Ⅰ级。残根需拔除。
此类致病菌高度敏感的抗生素为（）。
A.甲硝唑
B.青霉素
C.链霉素
D.庆大霉素
E.氯霉素
He loved his family, but seldom _______ spend much time with them.
A．was he able to
B．he was able to
C．is he able to
D．he is able to
残根需拔除。