Once upon a time Jimmy had a mother who told him that he was good at music. Jimmy wanted to play music. He did not know which instrument to play, so he tried a piano first. The piano went like a sound. Then he tried a guitar. The guitar played. His brother told him that the piano was better to start, so Jimmy played the piano. He hammered on the keys. Jimmy's brother liked this, but mom did not like this. Jimmy tried playing very quiet. Jimmy's mom liked this, but Jimmy's brother did not like this. Jimmy tried playing in the middle. Jimmy liked this, and Jimmy's mom liked this, and Jimmy's brother liked this. It was great.

When Jimmy hammered on the keys, who didn't like it?

The highest point of a wave is the crest. The lowest point is the trough. The vertical distance between a crest and a trough is the height of the wave. Wave height is also called amplitude. The horizontal distance between two crests is the wavelength. Both amplitude and wavelength are measures of wave size. The size of an ocean wave depends on how fast, over how great a distance, and how long the wind blows. The greater each of these factors is, the bigger a wave will be. Some of the biggest waves occur with hurricanes. A hurricane is a storm that forms over the ocean. Its winds may blow more than 150 miles per hour! The winds also travel over long distances and may last for many days.

What is the difference between wavelength and amplitude?

The French have always wanted to know what it means to be aFrenchman. Their history has been a constant quest for national identity: a conflict between strong regional loyalties and central authority. In about 2000b.c. Celtic tribes probably from eastern Europe came looking for greener pastures in the areas that are now Franche-Comte, Alsace, and Burgundy. At the same time, migrants from the Mediterranean countries were trickling into the south. The first recorded settlement was the trading post set up by Phocaean Greeks from Asia Minor at Massalia (Marseilles) around 600b.c. , followed by other ports at Hyeres, Antibes, and Nice. But the Greeks developed few contacts with the interior beyond a little commerce in olives and wine with the Celts of Burgundy. When their position was threatened by Ligurian pirates at sea and warlike tribes from inland, the merchants of Marseilles called on Rome for help. From Gaul to France In 125b.c. , the Romans came in force, conquered the "Gallic barbarians," and set up a fortress at Aquae Sextiae (Aix-en-Provence). They took advantage of this new stronghold to create Provincia (now Provence), stretching from the Alps to the Pyrenees, in order to guarantee communications between Italy and Spain. When this province was endangered by fresh attacks from the north, Julius Caesar himself took charge, conquering practically the whole of Gaul by 50b.c. Caesar drew Gaul's northeastern frontier at the Rhine, taking in present-day Belgium, and warned that the Germanic tribes across the river the Franks (after whom France is named), Alamans, and Saxons would always threaten the security of the frontier. The Romanization of Gaul sent the most energetic warriors to defend the outposts of the empire while their families settled down to work the land or build towns such as Lyon, Orange, Arles, and Nimes, and the first great highways between them. At the same time, merchants built up a thriving trade with the rest of the Roman Empire. The pattern for the peasantry and bourgeoisie of France was thus established. Christianity was introduced into Gaul in the first century a.d.
What was happening in France in about 2000 BC?