题目

Johnson failed the test again, because he didn't study hard and __________ forgot to do his homework. A . always B . hardly ever C . never 答案：A12．如果$\frac{x}{2}$=$\frac{y}{3}$，那么$\frac{7{x}^{2}-{y}^{2}}{{x}^{2}-2xy+3{y}^{2}}$=1．