下列天然纤维中不属于短纤维的是()。
A.棉纤维
B.麻纤维
C.丝纤维
D.毛纤维
参考答案:C
These are Victor and Tina. _____ my brother and sister. [ ]
A. He's
B. She's
C. They're
D. That's
蛛网膜下腔出血最常见的病因是
A.高血压
B.脑动脉粥样硬化
C.先天性脑底动脉瘤
D.脑血管畸形
E.血液病