已知a≥0，b≥0，求证：a⁶+b⁶≥ab（a⁴+b⁴）．

下列各组反应中，不能用同一个离子方程式表示的是（   ）

    Here are t____ pictures. A man and a boy are in one picture. Who are they? L____ me tell you. The man is Mr. White, and the boy's n____ is Bill. He's the man's son. Now they are in Bill's bedroom. We can see some Chinese b____ on his desk. And on the bed, t____ is a shirt. It's Bill's. His trousers are on it, too.

    Now let's l____ at the other picture. You can see a woman and a girl in it. The woman is Bill's m____ and she's in her daughter, Ann's room. You can see a photo o____ the Whites on the white wall. W____ that on the floor? Oh, it's Ann's hat. but it looks l____ a brown cat.