按要求写单词

若y＝f(x)既是周期函数，又是奇函数，则其导函数y＝f′(x)(　　)．

某溶液能与锌片作用产生H₂，则该溶液中可以大量共存的离子组是（   ）

读一读，判断句子正误。
    Peter draws a monster(怪物). It's tall and strong. It has a big head and a big body. Its earsand eyes are small. Its mouth is very big. Its teeth(牙齿) are sharp(锋利的). It has two long arms. Its arms arevery strong. It has two big hands. It has two long legs and two big feet. Itcan run very fast(快).

下列关于日本的地形特点的叙述，正确的是