Which of the following choices best describes the role of taxes on the after-tax cost of capital in the U. S. from the different capital sourcesCommon equity Preferred equity Debt（）①A. No effectDecrease Decrease ②B. DecreaseDecrease No effect ③C. No effectNo effect Decrease

A. ①

B. ②

C. ③

有以下语句段
int n1=10，n2=20；
printf(" 【7】 "，n1，n2)；
要求按以下格式输出n1和n2的值，每个输出行从第一列开始，请填空。
n1=10
n2=20