肠出血型大肠埃希菌的血清型是______。
参考答案:O157:H7
The woman is fifty, but she looks ________.[ ]
A. new
B. young
C. thin
D. old
确认小脑扁桃体延髓联合畸形,一般认为扁桃体低于枕大孔()
A.10mm
B.7.5mm
C.6.0mm
D.5.0mm
E.4.0mm