In order to more accurately estimate the cost of equity for a company situated in a developing market, an analyst should:（）

A. add a country risk premium to the market risk premium when using the capital asset pricing model (CAPM).

B. add a country risk premium to the risk-free rate when using the capital asset pricing model.

C. use the yield on the sovereign debt of the developing country instead of the market risk premium when using the capital asset pricing model.

射流泵的（）、（）、（）之间关系的特性曲线，称为射流泵的有量纲特性曲线。