砭石
参考答案：
解析：是一种锐利的楔型石块，也是我国最古老的医疗工具，用来切开脓肿和排脓放血。
Miss Zhao is very helpful. She often helps us ____we are in trouble.
A．whether
B．although
C．whenever
D．however
普通型流脑临床特征性体征是皮肤（）.
A.瘀点或瘀斑
B.水疱
C.黑痂
D.斑丘疹
E.脓肿
