“Sorry” is a word that people in Britain often say in their daily life.

    One day while I was w____on the street, a young man ran by hurriedly, brushing(轻擦) against my handbag. He continued his way, but turned b____and said “sorry” to me. Even in a rush, he didn't f____to say “sorry”. One day, after I bought some bananas, the shopkeeper was passing me the change, but I wasn't ready for it and a coin dropped onto the ground. “Sorry, Madam,” he said w____bending to pick it up. I was s____why he said “sorry” to me. Another time, I stepped on a man's f____at the entrance to a cinema. At the same time, we b____said “sorry”.

    Slowly, I got to know that when something unpleasant happens in daily life, the British don't c____much about who is wrong. If someone is in trouble, a “sorry” is always n____. Perhaps that is w____I seldom see people quarrel on the buses or streets in Britain.

生态系统中碳循环的主要形式是（　　）

如图是一个正方体的表面展开图，请回答下列问题：

（1）与面B、C相对的面分别是？

（2）若A=a³+a²b+3，B=a²b﹣3，C=a³﹣1，D=﹣（a²b﹣6），且相对两个面所表示的代数式的和都相等，求E、F分别代表的代数式．