瓦斯检查员必须经过培训，取得（）后，持证上岗。
参考答案：安全技术工种操作资格证
I know how busy you must be and naturally I wouldn't want to ______ too much of your precious time. [ ]
A. take off
B. take up
C. take down
D. take out
从几何上看，詹森指数表现为基金组合的实际收益率与SML直线上具有相同风险水平组合的期望收益率之间的偏离。( )
