皮皮学，免费搜题
登录
搜题
【单选题】
How to construct new feature space by PCA?A.
New feature space by PCA is constructed by choosing the most important features you think.
B.
New feature space by PCA is constructed by normalizing input data.
C.
New feature space by PCA is constructed by selecting features randomly.
D.
New feature space by PCA is constructed by eliminating the weak components to reduce the size of the data.
拍照语音搜题，微信中搜索"皮皮学"使用
参考答案：
参考解析：
知识点：
皮皮学刷刷变学霸
举一反三
【简答题】在物质的量浓度均为 0.01mol·L -1 的CH 3 COOH 和CH 3 COONa的混合溶液中，测得c(CH 3 COO - )> c(Na + )，则下列关系正确的是 [ ] A .c(H + )> c(OH - ) B.c(H + ) c(CH 3 COO - ) D.c(CH 3 COOH)+ c(CH 3 COO - )= 0.01mol·L -1