对财富的渴求促成了地理大发现的出现。

单项选择题If corn farmers know that the demand for corn is inelastic, and they want to increase their total revenue, they should allA. plant more corn so that they would be able to sell more each year.B. increase spending on fertilizer in an attempt to produce more corn on the acres they farm.C. reduce the number of acres they plant in corn.D. contribute to a fund that promotes technological advances in corn production.

单项选择题关于血细胞染色，正确的是