组成人的前臂骨的是[ ]
A．胫骨和腓骨
B．只有肱骨
C．腕骨和掌骨
D．尺骨和桡骨
答案：D
Victor apologized for _________ to inform of the change in the plan.
A．his being not able
B．his not being able
C．him not to be able
D．him to be not able
母乳是婴儿最理想的天然食物，提倡纯母乳喂养6个月。1岁以下婴儿不宜食用（）。
A.牛奶
B.鲜奶
C.酸奶
D.奶粉
