If you walk along the River Thames, there are lots of interesting buildings to see. Running through the heart of London, there are also many galleries, markets, shops and activities to keep you busy along its banks. You will also see a strange round building. It looks very old and very different from all the others, This is Shakespeare's Globe Theatre (莎士比亚环球剧场).

    The Globe Theatre was first built here in 1599. William Shakespeare was one of the most famous writers that ever lived. His plays were performed in the theatre for many years. However, in 1613, a fire broke out during a performance. The theatre was destroyed (毁坏), but the second was built the following year. It remained a theatre until 1644, and then it was pulled down to build houses. The modern (and also the third) Globe Theatre was completed in 1997, over 350 years later. This was done to honor Shakespeare, the most famous English writer. To this day, his many plays are performed there daily. He wrote around thirty-eight plays. They are comedies (funny stories), histories (about historical events and people), and tragedies (serious and sad stories). People come from all over the world to watch them at the Globe Theatre. They are performed in exactly the same way as they were hundreds of years ago.

    The building is round and made mostly of wood. There are simple seats on three different levels all around the sides. Everyone can see the stage (舞台). However, there is no roof (屋顶) in the middle! The cheapest tickets are standing tickets. You stand in the middle, right in front of the actors, but if it rains, you will get wet!

    A lot of animals travel from one place to another. We call this migration.

    In Africa, large animals, like elephants and zebras, migrate to find food and water. They usually follow the same ways every year.

    A lot of birds migrate to find food and better weather, too. They are usually birds that eat insects. They spend the summer in northern Europe, because there are lots of insects there. In the winter there aren't any insects, so the birds fly south to southern Europe and Africa.

    Some insects migrate, too. In North America, millions of monarch butterflies fly south to spend the winter in Mexico, California and Florida, where it's warmer. They travel 50-65 km each day and they travel about 1, 125 km.

    Some fish migrate to breed (繁殖). Salmon (鲑鱼) can swim over 20, 000 km in their life. They are born in rivers in Ireland, Scotland and other places in northern Europe. The young fish swim down the river to the sea and into the Atlantic Ocean. They live in the ocean until they are adults. Then they return to the river where they were born. They lay their eggs in the river and then they usually die. Salmon do this, because their eggs are safer in the river. Other fish can't eat them.

    Arctic terns (北极燕鸥) travel the furthest when they migrate. They spend the summer in the Arctic, but when winter comes they fly to the Antarctic, because it's summer there. The next year they fly back to the Arctic again. In one year these small birds travel 36, 000km from one end of the earth to the other and back again. Nobody knows how they do it.

    Billions of locusts (蝗虫) are moving through farms and fields in the East African countries of Ethiopia, Kenya and Somalia.

    Locusts are grasshoppers. Normally grasshoppers don't travel in groups and so they do little harm. But when there are lots of them, their bodies and behavior change. That's when they become locusts. Locusts travel in huge groups, laying eggs along the way, which produce even more locusts. In a single day, a small swarm (群) of the insects can eat as much food as 35,000 people do.

    The locust swarms in Ethiopia and Somalia are the worst in 25 years. These locusts are desert locusts. They began swarming about six months ago. By moving with the winds, desert locusts can travel up to 90 miles a day or more.

    Locust swarms are more common when heavy rains follow a long dry period. The insects lay their eggs in the wet ground. This season, East Africa has had its heaviest rainy season in 40 years.

    When the insects swarm, one square kilometer of land can hold as many as 150 million locusts. There are 700 square kilometers of land covered by the insects in Kenya alone.

    The insects are a threat to lives in the region, where food is already in short supply. Already many farmers who keep animals are struggling because locusts have eaten out the plants the animals usually live on.

    In East Africa, farmers have been shooting into the air or making noises in the fields, but that doesn't work against so many insects. Experts say that spraying pesticides (杀虫剂) over large areas from airplanes is the only way to reduce the number of insects. The UN has released (释放) $10million to help deal with the locust problem. The UN says about $70 million is needed to truly control the locusts with pesticides.