将下列段落翻译成中文 Bio-diesel is best developed in EU.Its main raw material is colza oil. In 2003, yield of bio-diesel in Europe was more than 1.76 million tons. It is expected that by 2010, the number would reach 8.3 million tons. Germany is the biggest bio-diesel producing country in the world, and also the country in which biodiesel oil is used most widely in Europe. At present, there are 23 bio-diesel oil producers in Germany with annual production over 2.0 million tons, accounting for more than a half of the total production of 15 countries in EU.