The samplingrepresentative is made based on the individual deviation of phosphate rock by statistical method.
采用统计方法，针对原料磷矿个体差异，解决磷矿采样的代表性。
2
Sampling and interviewing respondents by cell phone is now a necessity if telephone surveys are to provide valid, reliable and representative data.
如果想通过电话调查提供有效、可靠和有代表性的数据，现在有必要开展移动电话抽样和采访工作。
3
Some professors like to test by sampling—that is, by asking you about a representative part of the issue, then assuming that you could do as well about the rest.