【单选题】听力原文: What is cloning? Cloning is the creation of cells or whole animals using DNA from a single 'parent', bypassing the normal reproductive process. The clone has the same DNA as the parent. The most...
【简答题】For centuries, people have been pushing the limits of what they can do. But it seems that these days the limits are getting higher and higher. Normal waves are big enough for experienced surfers. They...