Why Can't Humans Fly

Why can't humans fly? Written by Sarah Fleming. Illustrated by Wes Low.

《人类为什么不会飞？》 作者：莎拉·弗莱明 绘者：韦斯·洛

Why can't humans fly? Birds are the right size and shape to fly. This bird is too big to fly.

人类为什么不会飞？ 鸟类的体型和身形刚好适合飞行。 这种鸟体型太大，飞不起来。

Humans are not the shape or size to fly. We don't have wings. To have big enough and strong enough wings, we'd need big and strong enough muscles to flap them. To have big enough muscles, we'd need to have huge chests that stuck out more than a metre. Even if we were shaped to have wings, we couldn't fly unless we changed in other ways. For a start, we're too big and heavy. Like birds, we'd need to make our bones hollow to be light enough to fly. Just adding wings wouldn't allow us to fly. We'd need to change our bodies too. Our shape and size controls what we can and can't do.

人类的身形和体型都不适合飞行。我们没有翅膀。要是想拥有足够大、足够强壮的翅膀，我们就得有足够粗壮有力的肌肉来挥动翅膀。 要长出这么强壮的肌肉，我们的胸口就得向前突出一米多才行。 就算我们的身形条件适合长翅膀，我们也得做出其他改变才能飞起来。首先，我们体型太大太重了。和鸟类一样，我们得长出中空的骨骼，才能轻到足以飞起来。 光长翅膀可没法让我们飞起来，我们还得改造自己的身体。我们的身形和体型决定了我们能做什么、不能做什么。

Size and Shape Animals come in lots of different shapes and sizes. Some animals use their size or shape to help them to survive. Camels can store food for long journeys in the desert. A squid can't walk, but its streamlined and flexible shape helps it to swim very well.

体型与身形 动物的身形和体型多种多样。 有些动物靠自己的体型或者身形生存。 骆驼可以储存食物，支撑自己完成沙漠中的长途旅行。 鱿鱼不会走路，但它流线型的柔韧身体能帮它游得特别快。

Giraffes live in the African savanna. They compete for food with other leaf eaters, like antelope. The advantage of having a long neck is that a giraffe can reach food that others can't. Tiny pond skaters can walk on water to catch fallen insects.

长颈鹿生活在非洲稀树草原。 它们要和羚羊等其他植食动物争夺食物。 长脖子的好处是，长颈鹿够得到其他动物够不到的食物。 小小的水黾可以在水面行走，捕捉掉落的昆虫。

Female peacocks want to mate with the biggest and best male they can find. This is so that their babies will be bigger and less likely to be attacked. So male peacocks have big tails to attract a mate. The male peacock's tail lifts and opens up to attract a mate.

雌孔雀会尽量找体型最大、最优秀的雄孔雀交配。 这样它们的宝宝体型会更大，更不容易被攻击。 所以雄孔雀长着大大的尾羽来吸引配偶。 雄孔雀会抬起尾羽开屏，以此吸引配偶。