| 1. | It had a small brain, apparently walked upright, and had teeth more like those of a human than an ape .
它的脑子小，显然直立行走，牙齿与猿类比较更象人类的牙齿。 |
| 2. | Perhaps because it ' s just plain easier
可能这是因为直立行走要容易得多。 |
| 3. | Perhaps because it ' s just plain easier
可能这是因为直立行走要容易得多。 |
| 4. | Why did humans evolve to walk upright
人类为何进化到了直立行走的姿态？ |
| 5. | Well , that ' s impossible . i walk upright
可是,那是不可能的,我直立行走 |
| 6. | Make that " energetically less costly , " in science - speak
用科学术语来说，直立行走能“节省能量” 。 |
| 7. | Make that " energetically less costly , " in science - speak
用科学术语来说，直立行走能“节省能量” 。 |
| 8. | The remains of a tail lost long before man began to walk upright six million years ago
六百万年前人类开始直立行走很早以前，尾部的残余就丧失了。 |
| 9. | Now researchers say learning to walk millions years ago was not without its trials
研究人员指出，数百万年前，早期人类学习直立行走的过程并不简单，我们的一些早期祖先还是八字脚。 |
| 10. | " we think about the evolution of bipedalism as one of first events that led hominids down the path to being human .
“双腿直立行走的进化是原始人向人类进化的最初阶段中的一步。 ” |
