Camels can cross the desert for days without food. That is because the big hump on a camel's back stores fat, and that fat gives them energy. How does the second sentence connect to the first?

Emperor penguins crowd into a tight huddle during Antarctic storms. The birds packed in the middle of that huddle stay far warmer than a penguin standing alone. How does the second sentence connect to the first?

Monarch butterflies leave Canada and the northern United States in the fall. They flutter south for weeks and finally settle in the fir forests of central Mexico. How does the second sentence connect to the first?

A frog has smooth, damp skin and long back legs for leaping. A toad, on the other hand, has bumpy, drier skin and shorter legs for hopping. How does the second sentence connect to the first?

A scout honeybee that finds flowers hurries back to the dark hive. She dances in a figure eight, and the angle of her waggling run tells the other bees which way to fly. How does the second sentence connect to the first?

A sleeping sea otter floats on its back, and the moving tide keeps tugging at it. So the otter wraps a long strand of kelp around its body before it dozes off. How does the second sentence connect to the first?

First you stir flour, water, salt, and yeast into a sticky dough. Second you knead that dough on the counter until it turns smooth and springy. How does the second sentence connect to the first?

Before a winter storm, trucks spread salt across the roads in many towns. Salty water must get much colder than plain water before it will freeze. How does the second sentence connect to the first?

An ostrich stands taller than a grown man and cannot fly at all. The bee hummingbird of Cuba weighs less than a penny and can hover in one spot. How does the second sentence connect to the first?

A beaver drags branches and mud into a stream until the water stops flowing. As a result, a deep, quiet pond spreads out behind the new dam. How does the second sentence connect to the first?

A tadpole hatches from a jelly-covered egg and breathes underwater with gills. Weeks later it grows legs, loses its tail, and hops onto land as a young frog. How does the second sentence connect to the first?

A barn owl can drop onto a mouse without the mouse ever hearing it coming. Soft, comblike fringes along the edges of the owl's feathers break up the rush of air. How does the second sentence connect to the first?

First, farmers tap their sugar maple trees in early spring and collect the watery sap. Then they boil that sap for hours until it thickens into syrup. How does the second sentence connect to the first?

An oak spreads wide, flat leaves to catch as much sunlight as it can. Unlike the oak, a saguaro cactus has only sharp spines and stores water in its thick stem. How does the second sentence connect to the first?

A shark pulls oxygen out of the water through the gill slits on its sides. A dolphin, however, must swim up to the surface and breathe air through a blowhole. How does the second sentence connect to the first?

A Venus flytrap can snap shut on a fly in less than a second. Tiny hairs inside the open trap send a signal when an insect brushes against them twice. How does the second sentence connect to the first?

At the recycling center, a giant magnet first lifts the steel cans off the moving pile. Next, a spinning magnet pushes the lighter aluminum cans onto their own belt. How does the second sentence connect to the first?

In the Sonoran Desert, very little rain falls, and the ground bakes in the summer sun. In the rain forest of Puerto Rico, on the other hand, rain falls on most days of the year. How does the second sentence connect to the first?

A python can swallow a whole rabbit and then eat nothing at all for weeks. A tiny shrew must catch food almost every hour or it will starve. How does the second sentence connect to the first?

Both a violin and a guitar make sound from strings that vibrate. A violin's strings are stroked with a bow, while a guitar's strings are plucked with fingers. How does the second sentence connect to the first?