NO.PZ2022123001000080
问题如下：
An analyst collects data relating to five commonly used measures of financial leverage and interest coverage for a randomly chosen sample of 300 firms. The data come from those firms' fiscal year 2013 annual reports. These data are best characterized as:
选项：
A.time series B.longitudinal C.cross sectional解释：
Data on some characteristics of companies at a single point in time are cross-sectional data
因为从300个公司里面抽样所以是crossed sectional?
