A、By the color. B、By the size. C、By the taste. D、By the shape. A文中提到，判断胡萝卜是否可以收成的最好方式是看颜色。通常，颜色越亮，昧道就越好。故答案为A)。

When people think of carrots, they usually picture in their mind a vegetable that is long, thin and orange. But carrots come in many different sizes and shapes. And not all carrots are orange. (32) For example,Paris Market carrots are about 5 centimeters around,and Belgian White carrots are,as their name suggests,white.
    For the best results, carrots should be grown in sandy soil that does not hold water for a long time. The soil also should have no rocks. Weather, soil conditions and age will affect the way carrots taste. (33) Experts say warm days,cool nights and a medium soil temperature are the best conditions for growing carrots that taste great.
    Carrots need time to develop their full sugar content. This gives them their taste. If they are harvested too early, they will not have enough sugar. But carrots loose their sweetness if you wait too long to pull them from the ground. (34) The best way to judge if a carrot is ready to be harvested is by its color. Usually, the brighter the color, the better the taste.
    Many people do not know that carrots can be grown during the winter months. (35) If the winter is not cold enough to freeze the ground, you can grow and harvest carrots the same way as during the summer months. If the ground does freeze in your part of the world,simply cover your carrot garden with a thick layer of leaves or straw. This will prevent the ground from freezing. You can remove the ground cover and harvest the carrots as they are needed.
32. What do we learn about Paris Market carrots?
33. What is good for growing carrots according to experts?
34. Which is the best way to judge if carrots are ready to be harvested?
35. What does the passage say about growing carrots in winter?