用不等号“>、<、≥、≤”填空:a2+1 ____0.
阅读下面的一段话,判断正误。
Hi! I'm John. Come here, my friends! Look at my dog. It has two big eyes. It's very cute. This is my cat, Mimi. It's fat. It's two years old. I have six fish. Oh! Mimi likes(喜欢) my fish. I have a bird, Polly. It's beautiful!
亚洲和北美洲分布范围最广大的气候都是
按要求改写句子。
在柠檬中插入两种不同的金属可以制得水果电池。相同条件下,水果电池的电压与两种金属的活动性差异大小有关。下列柠檬电池的两种金属,活动性差异最大的是( )