链球菌引起化脓性病灶脓汁稀薄且易扩散,其主要原因是病原菌能产生()
A.透明质酸酶
B.血浆凝固酶
C.链激酶
D.链道酶
E.溶血毒素
参考答案:A, C, D
She is an easy-going girl._______ you meet her , she will smile to you.
A.As
B.Every time
C.While
D.Since
木材在使用前应进行干燥处理,窑干木材的含水率是:()
A.12%~15%
B.<12%
C.15%~18%
D.18%~21%