若5m﹣3n=﹣4，代数式2（m﹣n）+4（2m﹣n）+2的值为____
Megan failed to read Huw's letters because _______.
哺乳动物后代的成活率比其他动物要高，其主要原因是
— The storybook is very interesting.
— I agree with you. I ______it twice already.
判断正误
