读一读,选一选
____ Is your father here today? A. No, I don't.
____ What does your mother do? B. He's a businessman.
____ Do you want to be a head teacher? C. No. He's in Australia.
____ What does he do? D. She's a head teacher.
如图所示,在光滑水平面上放置两滑块A、B,滑块B左端连有轻质弹簧,现使滑块A以4m/s的速度向右匀速运动,并与静止的滑块B发生碰撞,已知滑块A、B的质量分别为1kg、3kg,求二者在发生碰撞的过程中:
如图所示是物质在熔化时温度随时间变化的图像,下列从图像中获得的信息不正确的是( )
根据提示写出单词。