如图所示,质量相等的A、B两物体在平行于固定斜面的推力F的作用下,一起沿光滑斜面做匀速直线运动,A、B间轻弹簧的劲度系数为k,斜面的倾角为30°,则弹簧的压缩量为( )A. B. C. D.
--How old _____ you? --I am twelve. A. am B. are C. is
--Do you like candy? --__________. A. Yes, I do. B. Yes, I am. C. Yes, I can.
--_____ that, mum? --It’s a taxi. A. What B. What’s C. Who’s
--Have _____ apple, please. --Thank you. A. an B. the C. a
--How old is your sister? --___________. A. I’m seven. B. She’s seven. C. He’s six.