人们都知道如果身上痒,通常抓几下就能解决问题。但这究竟是何原理?美国科学家通过科学实验,揭开了“抓痒”的奥秘。原来抓痒能让向大脑传递刺激的神经细胞变得“迟钝”,从而减轻痒感。这一事实表明①思维和存在具有同一性 ②意识是人脑对客观事物的正确反映③实践是认识的来源 ④规律的存在和发生作用不以人的意识为转移
—When ________ you ________ to learn to skate? —Five years ago.
Ten minutes ago,there ________ an eraser,a pen and some books on the desk. A.was B.were C.is
—What did you do yesterday evening,Gina? —I ________ Titanic 3D in the City Cinema.
—________ he go to Central Park? —Yes,he did.
—Sam didn’t go to school yesterday,did he? —________.He was ill yesterday.