Most kinds of rose plants come from Asia. But roses are also native to other areas including northwest Africa, Europe and the United States. In 1986, Congress chose the rose as American’s national flower. Technically, Congress and President Ronald Reagan declared it the “national floral emblem（国花）.” Whatever the name, the decision did not smell sweet to supporters of other popular flowers.
Some people say roses are difficult to grow.  But you have a good chance of success if you start with a few suggestions from experts. You should plant your roses where they can get sunshine for about six hours on bright days. You can buy roses from a garden center or by mail order. You can buy potted roses, also known as container roses, or bare-root plants. Each kind has its fans.
Some gardeners say potted roses are easier to plant. They say the roots develop better. But Jeffrey Dinslage, an expert, points out that bare-root roses come without soil. So they weigh less to transport.
Another expert advises getting bare-root roses as close to planting time as you can.. If they arrive before you are ready to plant them, make sure the packing material is moist. Keep the plants in a cool, dark place. The resting plants have no leaves but still need water. When growing roses, the soil should feel moist deep down. Watering should be done in the morning.
But do not water too much. People often ask Jeffrey Dinslage about unhealthy discoloration on rose leaves. He says the spots are usually caused by too much water. After heavy rains or too much watering, he advises pulling away mulch, the substance used to protect the roots, to improve the quality of the soil, temporarily from around the roots. This will help dry the soil.
From the first paragraph, we know that in the United States _______.

A．all the people like roses

B．there are a lot of national flowers

C．some roses don' t smell sweet

D．there are some other popular flowers

How many kinds of roses can you buy according to the passage?

A．One.

B．Two.

C．Three.

D．Six．

Why does Jeffrey Dinslage suggest planting bare-root roses?

A．They are easier to plant.

B．Their roots develop better.

C．They are cheap to transport.

D．Their leaves need no water.

Which of the following is closest in meaning to the underlined word “moist”?

A．Slightly wet.

B．Pretty dry.

C．Too hard.

D．Lightly soft.

According to Jeffrey Dinslage, people should _______ to avoid the sports on rose leaves.

A．not water roses in the morning

B．protect the roots of roses

C．improve the quality of the soil

D．not water roses very much