因为a2=(a)2=a，所以a≥0．
属于滴虫 * * 炎临床表现的项目包括
A.脓性、泡沫状分泌物
B.外阴部瘙痒
C.经期之后自觉症状加重
D. * * 黏膜有散在出血点
E.小阴唇内侧附着白色块状物
She asked Linda if ______go and get some. [ ]
A. could she
B. she could
C. she can
D. she may
