小乔木中观花或观果的种类较多，尤其是观花树种，花感强烈，园林中应用普遍，如（）。
A.夹竹桃
B.木芙蓉
C.腊梅
D.红檵木
参考答案：D
He was generous with his time, ______ I was grateful..
A．for which
B．at which
C．with which
D．with which
作为肠内营养制剂糖类的主要来源有（）
A.乳糖
B.果糖
C.α－葡聚糖
D.糊精
E.β－葡聚糖
