题目

半径为R光滑球恰好放在木块的圆槽中，OA与水平成θ角，圆球质量为m，木块质量为M，不计摩擦，求：人手至少用多大恒力F垂直向下拉木块B端，球才可离槽？ 答案： be pleased with, be ready for,from now on,can't wait,be good at1._______  you       the coming basketball match?2. Lin Feng always studies hard at English, so he      it.3. Bill comes first in the exam. His father     him.4. Jack, one of my old friends, is coming to see me. I      to see him.5. In order to lose weight，I will eat less meat