蛋白质水解时
A．一级结构破坏B．二级结构破坏C．三级结构破坏D．四级结构破坏E．空间结构破坏
参考答案：A
根据句意，补全单词。
1. The___ _of Qomolangma is 8,848 kilometers.
2. food is well kept.
3. The Himalayas _ climbers from all over the world.
4. The___ _ is about 3,000,000 in this city.
5. He's ____ his Olympic dream.
用四根木条钉成的长方形，拉成平行四边形后，它的周长和面积都保持不变．______．
