A:胃蛋白酶催化蛋白质水解时需要ATP供能
B:在细胞质内合成的酶只能在细胞质内发挥作用
C:酶与底物结合后会改变构象形成酶﹣底物复合物
D:高温和低温均能破坏酶的结构使其失去生物活性
—Have you ever _______ to bring your homework to school?
—Yes. I _______ it at home once last term.
I enjoyed ________ exciting stories when I was young.