【推荐1】The abacus was invented in China thousands of years ago. It is usually made of wood and has many beads. By _____________the beads up or down, one can finish lots of math problems. It is a joy to watch an old man use an abacus. Fingers move, beads knock, and the _____________comes out a few seconds later. However, it requires lots of _____________to use the abacus well. In the past, the use of the abacus was taught in all schools. It usually takes the students several years to master this skill completely.

Today, abacuses have become a _____________although they are no longer widely used. Abacuses used to be a must-have for businessmen, _____________some people believe that abacuses are helpful for gathering wealth.

【推荐2】The Crystal Palace was a cast iron and plate glass structure originally ______ in Hyde Park, London, to house the Great Exhibition of 1851.

The exhibition took place from 1 May to 15 October 1851, and more than 14, 000 ______ from around the world gathered to ______ examples of technology developed in the Industrial Revolution. ______ by Joseph Paxton, the Great Exhibition building was 1,851 feet（564 m） long, with an inside height of 128 feet（39 m）. It was three times the ______ of St Paul’s Cathedral.

The introduction of the glass sheets method into Britain by Chance Brothers in 1832 made ______ the production of large sheets of cheap but strong glass. Its ______ in the Crystal Palace created a structure with the greatest area of ______ ever seen in a building. It ______ visitors with its clear walls and ceilings that did not ______ inside lights.

It has been said that the name of the building _____ from an article by the playwright （剧作家）Douglas Jerrold. He wrote in a magazine called Punch about the coming Great Exhibition, ______ to a “palace of very crystal”.

After the exhibition, the palace was moved to an area of South London known as Penge Common. It was rebuilt at the top of Penge Peak next to Sydenham Hill. It stood there from June 1854 until its ______ by fire in November 1936. The nearby residential（住宅的）area was ______ Crystal Palace after the landmark. Crystal Palace Football Club was founded at the site in 1905. The club still ______ Benjamin Waterhouse Hawkins’s Crystal Palace Dinosaurs which date back to 1854.

【推荐3】Eating fruits and vegetables is part of keeping a healthy diet. Health experts ______ people should eat five servings of fruits and vegetables a day. A(n) ______ way to remember this is to try to eat each color of the rainbow (彩虹) ______. This is because different colored fruits and vegetables contain different vitamins and minerals. ______ you eat one of each color each day, you are sure to ______ the necessary nutrition your body needs.

______ fruits and vegetables is good for the heart. There are many delicious ______ in this group. Have an apple with lunch. You can ______ have a red pepper for a hot tasty small meal. ______ some tomatoes and put them on your sandwich. Or ______ you can have strawberries after dinner. When you ______ red, your heart works better.

Orange and yellow fruits and vegetables contain vitamin C. Vitamin C helps the ______ protect itself against disease. In this way it helps your body stay in good health. ______, these wonderful foods are good for your sight. So it is a great ______   to have a glass of orange juice with breakfast. Then put some peaches in your lunchbox. Are you afraid of catching a cold? ______ that from happening by eating a juicy tangerine (a type of small sweet orange).

Green fruits and vegetables have long been widely known as healthy foods. ______, they are especially good for keeping teeth and bones strong. When you eat green, your smile will thank you! Your bones will thank you too!

Blue and purple fruits and vegetables are useful to the ______. They help with memory. Put blueberries in your bowl. You can easily ______ where you put your keys!

Eating the rainbow is an easy way to ______ yourself. So make your eating habits a little more ______!