in full sun.

Moving them out of the sun helps control an insect problem with leaf hoppers. Mr. Hoffman does not use pesticides （农药）. Instead, he plants the potatoes at the drip line, especially on the east side of the tree. The potatoes get morning sun, but they are shaded during the hottest part of the day. Leaf hoppers dislike shade, and the hottest part of the day is when they do the worst of their damage.

Time of day, brightness of the sun, shadows from trees, walls and buildings, these all influence how much sunlight falls or does not fall on plants. And extension agent Curtis Swift at Colorado State University says people interested in shade planting should also remember something else. The term “shade” can describe differen t amounts of darkness. He says it can even mean different things in different parts of the world.

28. What’s the author’s purpose of writing the passage？

A. T o show vegetables can be planted in the shade.

B. To recommend an approach to managing a website.

C. T o present a kind of eco-friendly lifestyle.

D. T o introduce Mark Hoffman and his family.

29. What can we infer from the second paragraph？

A. Food and flowers produce more in the shade.

B. Food growing in the shade contains more nutrients.

C. Sun can affect the production of some plants.

D. Food growing in the shade is the best choice for most plants.

30. By using asparagus as an example, the author wants to explain that______.

A. asparagus prefers to grow in the shade