As experts continue to study the science of risk-seeking, we’ll continue to hit the mountains, the waves or the shallow end of the pool.

本句是2016年高考英语北京卷的七选五的最后一句。我对句中 hit the mountains, the waves or the shallow end of the pool 不理解，我觉得the mountains 和 the waves 可以并列，但与the shallow end of the pool怎么能够并在一起呢？求解析！

附原文如下：

Sometimes we decide that a little unnecessary danger is worth it because when we weigh the risk and the reward, the risk seems worth taking. However, we are not all using the same reference standard to weigh risks and rewards. Some of us enjoy activities that would surprise and scare the rest of us. Why? Experts say it may have to do with how our brains work.

The reason why any of us take any risks at all might have to do with early humans. Risk-takers were better at hunting, fighting, or exploring. Being better at those things meant a greater chance of survival. As the quality of risk-taking was passed from one generation to the next, humans ended up with a sense of adventure and a tolerance for risk.

So why aren’t we all jumping out of airplanes then? Well, even 200,000 years ago, too much risk-taking could get one killed. A few daring survived, though, along with a few stay-in-the-cave types. As a result, humans developed a range of character types that still exists today. So maybe you love car racing, or maybe you hate it. It all depends on your character.

No matter where you are on the risk-seeking range, scientists say that your willingness to take risks increases during your teenage years. This is when you start to move away from your family and into the bigger world. To help you do that, your brain increases your hunger for new experiences. New experiences often mean taking some risks, so your brain raises your tolerance for risk as well.

New brain research suggests our brains work differently when we face a nervous situation. For the risk-seekers, a part of the brain related to pleasure becomes active, while for the rest of us, a part of the brain related to fear becomes active.

As experts continue to study the science of risk-seeking, we’ll continue to hit the mountains, the waves or the shallow end of the pool.