神经网络可分为（）、（）、（）和广泛前向网络。

IEEE802.11b的典型解决方案有( )解决方案，单接入点解决方案，多接入点解决方案与无线中继解决方案。

关于运动的合成与分解，下列几种说法正确的是（　　）

A．物体的两个分运动是直线运动，它们的合运动一定是直线运动

B．两个在同一条直线上的运动，其合运动的速度大小等于两分运动的速度大小之和

C．两个分运动的时间之和等于它们合运动的时间

D．速度、加速度和位移的合成都遵循平行四边形定则

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 America’s national flower. Technically, Congress and President Ronald Reagan declared it the “national floral emblem.” Whatever the name, the decision did not smell sweet to supporters of others 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 form 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, pint out that bare-root roses come without soil. So they weigh less to transport.

Another expert advises getting bare-foot 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, temporarily from around the roots. This will help dry the soil.

小题1: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小题2: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小题3:Which of following is closest in meaning to the underlined word “moist”?

A．Slightly wet.

B．Pretty dry.

C．Too hard.

D．Lightly soft.小题4:According to Jeffrey Dinslage, people should ______ to avoid the spots on the 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

某交易者于5月1日买入1手7月份铜期货合约，价格为64000/吨。同时卖出1手9月份铜期货合约，价格为65000元/吨。到了6月1日铜价上涨，交易者将两种合约同时平仓，7月与9月铜合约平仓价格分别为65500元/吨，66000元/吨，则此种情况属于______。

A．正向市场的熊市套利
B．正向市场的牛市套利
C．反向市场的牛市套利
D．反向市场的熊市套利

股道有效长度的起止范围由下列哪些因素确定（）。

A.出站信号机

B.车挡

C.站界

D.警冲标