根据短文，判断正误。
Look at this desk. It's Jim's desk. It's brown. Jim's book is on it. It's an English book. His pencil-box is on it, too. His pencil is in his pencil-box. But where's his pen? He can't find it.
将新鲜血取出加入抗凝剂静置一段时间后，其成分分成三层，中层的是（ ）
根据拼音写汉字，给划线的汉字注音。 为我们展现了一片丰富多彩的新天地。“长征之歌”专题再现了红军长征的动人情景，讴（ ）歌了红军战士的钢铁意志和伟大的民族精神；在“爱国情怀”专题里，我们似乎qīng（ ）听到海外游子思念故土的心声，体会到被剥夺使用母语权利的亡国者的痛楚，也品味了著名科学家始终眷（ ）恋祖国的深情，领悟了志士仁人面对山河破碎而壮志难chóu（ ）的忧愤，爱国之情油然而生······
下列变化中属于化学变化的是（ ）
