I think a good friend _____ me laugh. [ ]
A. takes
B. makes
C. let
D. have
答案：B
In our class, when the bell rang and the teacher closed his book, it was a____ for everyone to stand up. [ ]
A. signal
B. chance
C. mark
D. measure
下列有关朗格汉斯细胞组织细胞增生症的X线检查描述正确的是（）
A.胸片典型改变为肺野透亮度增加呈网状或网点状阴影
B.骨骼病变为溶骨性凿穿样损害
C.病变部位骨骼呈增生性改变
D.脊椎多表现为脊突破坏
E.不会累及骨盆骨或颌骨
