若1mol​与足量的稀硫酸混合加热使其水解，在所得乙醇分子中的氧原子含有的中子为（　　）

    My name is Tom. I come from England. I like to have friends who are different from me. My best friend is Paul. Paul is funnier, more outgoing and athletic than me. He always tells jokes and makes me laugh. We also like different things. He likes going to the movies. He likes playing sports. He likes pop music. But I like reading books. He often asks me to go to the movies and gives me some interesting books. And I often give him CDs. We often help each other.

She likes playing ________piano; her brother likes playing ________ basketball.

下列热带作物巴西产量居世界首位的是（ ）

在一天中我们的心跳快慢会发生一些变化，有些时候会感到心跳____，全身____；甚至流出汗来。