目前认为，MS的发病与_________、_________、_________有关。
参考答案：病毒感染与自身免疫反应；遗传因素；环境因素
—I heard that Mr Smith found a way to fix our computer.
—Really? That was very _____ of him. [ ]
A. generous
B. clever
C. easy
D. necessary
美容师要及时（）与顾客发生纠纷的隐患。
A.关注
B.认识
C.对面
D.发现和消除
