下列哪些运动不适合老年人选择（）
A.游泳
B.慢跑
C.散步
D.百米短跑
E.冷水浴
参考答案：D
I lost my watch last week, but today it _ under the bed. [ ]
A. was looked for
B. was found
C. was gone
D. was made
溶胶剂的性质是（）
A.分散相质点小于1nm
B.具有Tyndall现象
C.有双电层结构
D.有电泳现象
E.不易受电解质影响
