Imagine a product that can be used as medicine, a cleaning agent and a beauty treatment. You can eat it, drink its juice, and【C1】______essential oil from it. It is available all over the world, and is inexpensive. You may even have one in your kitchen【C2】______What is it? The lemon! It is thought that lemon【C3】______in Southeast Asia. From【C4】______they were gradually carried westward toward the Mediterranean. Lemon trees thrive in mild【C5】______, which is why they grow so well in places like Italy, Mexico, Spain, and even parts of Africa and Asia. A mature tree, depending on the variety and location, can produce【C6】______from 200 to 1, 500 lemons a year. The cultivated(培育的)varieties【C7】______in different periods, making it possible to harvest lemons all year round. You don"t need lots of space to grow a lemon tree. Even a sunny balcony(阳台)is enough,【C8】______small lemon trees can be grown in pots and can make your house beautiful. They like sunny, wind-free spots where they can soak up the warmth,【C9】______against a wall. However, if the temperature drops a lot during the winter, they need to be【C10】______or brought indoors.