干扰dUMP→dTMP的核苷酸抗代谢物是
A．6-巯基嘌呤B．氮杂丝氨酸C．别嘌呤醇D．甲氨蝶呤E．阿糖胞苷
参考答案：D
The ground is _______ with _______ leaves.
A．covering, falling
B．covered, falling
C．covered, fallen
D．covering, fallen
《书剑恩仇录》第六回《有情有义怜难侣无法无天赈饥民》，“难侣”是谁？
