以下哪种疾病累及脊髓前角细胞()
A.肌萎缩侧索硬化
B.进行性脊髓性肌萎缩
C.脊髓空洞症
D.脊髓灰质炎
E.脊髓亚急性联合变性
参考答案:A, B, C, D
He ________ a speaking competition this summer holiday. [ ]
A. takes part in
B. joined
C. took part in
销售精品中和客户有效沟通的四法则不正确的是()
A.强势介绍
B.提问
C.倾听
D.确认