更多护理试题
- 1语句dataframe.dropna(thresh=len(df)*0.9,axis=1) 表示如果某列的缺失值超过90%则删除该列。 （ ）
- 2—Is it true that Mike refused an offer from Yale University yesterday?—Yeah，but I have no idea _______ he did it；thats one of his favorite universities.
- 3( )动圈式弧焊变压器电流的细调节是通过改变一次线圈、二次线圈的距离来实现。距离越大电流减少。
- 4555定时器可以用外接控制电压来改变翻转电平。
- 5Jane moved aimlessly down the tree - lined street, not knowing ________ she was heading.
- 6下面关于打包编译的描述错误的是哪一项
