人教版（新课程标准）高中英语必修3 Unit 2 Healthy eating 同步练习2

    When you are travelling in Thailand, which means of transport is the best choice?

    You can rent a variety of motorbikes or bikes in Thailand. It seems to be very popular in most of the beaches and islands along the places in the north. The most popular bikes are the little 125 cc Honda Dream which you can get for about 150 baht (铢) a day or as little as 3,000 baht per month, making it the cheapest way to tour Thailand for the people from other countries.

    Sometimes you will have to go somewhere by taxi. When you are in cities in Thailand, especially in Bangkok, always remember to get a taxi that is traveling on the roads. Some drivers outside hotels refuse to use the meter(计程表). They will ask a price which is several times the price when they use the meter!

    The quality of the roads in Thailand is generally pretty good, so renting cars is another way to get around. The big car rental companies may offer you slightly older cars at a very reasonable(合理的) price. It is a little surprising considering that the cost of buying a car in Thailand is more than that in the West. Petrol is also reasonably priced in Thailand, more expensive than American prices, but much cheaper than what is paid in Europe. In the past, Bangkok could be a difficult place to drive in—signs were generally in Thai only, making it a hard job to find exactly where you were by looking around. But now, the situation is improved. In a lot of places, even the farthest corners of the country, street signs are in both Thai and English.

    There are lots of insects that farmers hate. But there also are some they like. They protect crops against damage from other insects. A good example is the lady beetle, which is also known as the ladybug(瓢虫)．

    Lady beetles are a natural control for aphids(蚜虫). Lady beetles are red, orange or black. They often have black spots, though some have light colored spots. Different kinds of lady beetles have different numbers of spots. There are lady beetles with four, five, seven and fourteen spots.

    Many of the well-known kinds of lady beetles come from Asia or Europe. They now are common throughout the United States.

    American scientists imported one kind of lady beetle, the multicolored Asian lady beetle, as early as 1916. They released them as an attempt to control some kinds of insects. Over the years, the beetle has become established, possibly helped by some that arrived with imported plants on ships.

    Experts say over 450 kinds of lady beetles are found in North America. Some are native to the area. Others have been brought from other places. Almost all are helpful to farmers.

    The Asian lady beetles now in the United States probably came from Japan. The Asian lady beetle eats aphids that damage crops like soybeans, fruits and berries.

    In the southern United States, Asian lady beetles have reduced the need for farmers to use reskilling poisons on pecan trees. This popular tree nut suffers from aphids and other pests that the lady beetles eat.

    But some people say the Asian lady beetle has itself become a pest. They worry that the lady beetles may eat their late autumn fruit crops.

    Experts say Asian lady beetles may appear in large numbers in some years. But they say the insects are too helpful to be considered as pests.