All of the following are drawbacks to using price-to-book value (P/BV) as a valuation technique EXCEPT:（）

A. P/BV valuation may give a misleading comparison of different types of business models.

B. P/BV is an unstable measure of valuation.

C. P/BV valuation does not adequately account for the positive impact of R&D expenditures.

单级振荡式发射机振荡器的输出功率可以直接满足雷达对发射功率的要求。