两种药物合用，能产生或增强毒性。这种配伍关系是（）
A.相杀
B.相畏
C.相恶
D.相反
E.相使
参考答案：D
The rich only ____ themselves in making money and had no eyes for the needs and welfare of their workers. [ ]
A. devoted
B. occupied
C. enjoyed
D. concerned
______ left when you get to the end of the street.
A．Keep
B．Keeping
C．To keep
D．Kept
