意大利作为德奥的战前盟友，在一战爆发后没有参加德奥集团，反而参加了协约国对后来的“盟友”作战，这最能说明第一次世界大战的（    ）

    Today is Saturday. It's nine o'clock. The Smiths ____ (be) all at home. Mrs. Smith is watching TV. She ____ (like) watching TV and shopping. She wants to buy ____ bike on TV, because she wants to ride it to work. Mr. Smith is ____ (read) a newspaper. There is some news about Liu Huan. And his favorite ____ (sing) is Liu Huan. He sings very ____ (good). Their son, Jim, is talking on the phone. He is calling one of his ____ (friend). He wants to go to the zoo to see animals with his friend. Their daughter, Lily, is playing ____ her small dog. She is only four years old. Look, she's eating a banana. This is ____favorite fruit. What's that over there? Oh, it's a cat. It's sleeping. Jim, please keep quiet ____ don't wake it up!

①用甲基绿对线粒体进行染色，可观察到蓝绿色颗粒状的线粒体

②验证酶的专一性实验时，需要将等量的淀粉酶分别加入2ml的淀粉和蔗糖溶液中，然后用碘液检测

③“观察DNA和RNA在细胞中的分布”和“观察花生子叶细胞中的脂肪颗粒”两个实验都需要显微镜

④纸层析法分离叶绿体中色素的实验中，橙黄色带在滤纸条最上边，判断胡萝卜素在层析液中溶解度最大

⑤CO₂可使溴麝香草酚蓝水溶液由黄变绿再变蓝，而酒精可使酸性条件下的重铬酸钾变成灰绿色

⑥用“高倍显微镜观察叶绿体和线粒体”和“观察植物细胞的质壁分离和复原”实验过程中细胞都保持活性状态

⑦探究温度对淀粉酶活性影响的实验，不能用斐林试剂代替碘液

⑧用于观察质壁分离与复原的紫色洋葱表皮细胞同样可用来观察植物细胞有丝分裂