题目

_______ made her excited was _______ she had managed to win her house back. A. That; when     B. It; that            C. What; that      D. What; whether   答案：C下列计算正确的是（ ）A．a•a2=a2 B．（a2）2=a4 C．a2•a3=a6 D．（a2b）3=a2•a3