石膏（）
A.主含硫化汞
B.主含含水硅酸镁
C.主含含水硫酸钙
D.主含二硫化二砷
E.主含碳酸锌
参考答案：C
I was just going to cut my rose bushes but someone it. Was it you? [ ]
A. has done
B. had done
C. would do
D. will do
下列等密度硬膜下血肿征象中错误的是（）
A.单侧脑沟、脑裂变窄，甚至消失
B.脑室受压变形，中线结构移位
C.白质挤压征
D.增强扫描血肿无增强
E.额板内出现低密度影
