题目

句型转换 1. She wears glasses every day.（改为否定句） She               glasses every day. 2. Tom’s sister has long straight yellow hair. （改为一般疑问句）           Tom’s sister       long straight yellow hair? 3. Wang Hai isn’t too tall or too short.（改为同义句） Wang Hai has               . 4. George is tall and thin.（就画线部分提问） What does George               ? 5. Maybe the woman with long black hair is her mother.(改为同义句） The woman with long black hair        15．如图所示，有一斜面长为5m，高为3m，现用力F沿斜面把重为10N的物体从底端匀速拉到顶端．已知物体受到的摩擦力为2N，则斜面的机械效率是75%．