请用化学符号填空： （1）3个二氧化碳分子 （2）2个亚铁离子 （3）氢氧

What rate of return will an investor earn if they buy a 20-year, 10 percent annual coupon bond for $900 They plan on selling this bond at the end of five years for $951. Calculate the rate of return and the current yield at the end of five years. Rate of return Current yield （）①A. 12.0% 10.51% ②B. 9.4% 11.00% ③C. 12.0% 11.00%

A. ①

B. ②

C. ③

无比山药丸可用治疗下列何种病证（）

A.气淋

B.癃闭

C.血淋

D.劳淋

E.尿浊

请在下图中请根据小磁针的指向标出螺线管N、S极及电源正负极．

一个类可以从直接或间接的祖先中继承所有属性和方法。采用这个方法提高了软件的______。