An analyst does research about capital structure. Which of the following is the least appropriate method to estimate the capital structure weights when a company's target capital structure is unknown to analysis

A. Using the book value of capital components.
B. Using industry average capital components.
C. Analyzing trends in capital components to infer the target capital structure.

话音记录器用于（）记录飞机的通讯和通话内容

A.连续

B.间断

C.起飞前

D.巡航中