Thetwomainpopular__________ofEasteraretheEasterbunnyandtheEasteregg.

若α1，α2，α3是Ax=b(b≠0)的线性无关解，证明α2-αl，α3-αl是对应齐次线性方程组Ax=0的线性无关解

—Howareyoutoday?—Oh,I__________asillasIdonowforalongtime.

I'msorryI'veforgottentopostyourletter.

—Nevermind._____postitmyself.

技术贸易中最常见、使用最广泛的交易方式是()