We use flowers as messengers to say something we might have trouble 【小题1】 (say) directly ourselves. Over time flowers have come to symbolize the most 【小题2】 (power) human experiences: beauty, love, hope, and rebirth. Sweet flowers alone can say what one 【小题3】 (fear) expressing. We've listed some of the most famous flowers that have an important meaning. In Mao Zedong's poem Ode to Plum Blossom《咏梅》, the plum blossom was used 【小题4】 (praise) soldiers who sacrificed their lives for Chinese people. 【小题5】 great Chinese poet Li Bai from the Tang Dynasty once compared Yang Yuhuan's beautiful face 【小题6】 blooming peonies (牡丹). Flowering in May, peonies' large petals and strong colors are linked to prosperity (成功) and richness. The orchid (兰花) is well known because 【小题7】 (it) delicate smell attracts lots of people. Beautiful articles and poems 【小题8】 (call) “lanzhang” by Chinese people in traditional Chinese culture. Roses, of course, have the most colorful meaning among all the flowers. Red roses mean “I love you.” A red rose, rather than yellow roses, acts as the traditional romantic gift 【小题9】 (give) to your love on Valentine's Day. Sending yellow roses can be risky, as they represent either friendship 【小题10】 envy.

You only have one pair of eyes, so take care of them! But do you know that it is tempting to think that your eyes are simply mirrors that reflect whatever is in front of them? Researchers, however, 【小题1】 ( show) that your brain is constantly working to create the 【小题2】 (impress) of an uninterrupted and continuous world. For instance, in the last 10 minutes, you have blinked (眨眼)your eyes around 200 times. You have probably not been aware of any 【小题3】 these interruptions in your visual world. Something you probably have not seen in a long time without the aid of mirrors 【小题4】 (be) your nose. It is always right there, down in the bottom comer of your vision, but your brain filters it out so that you are not aware of your nose 【小题5】 you purposefully look at it. Nor are you aware of the artery (动脉) 【小题6】 ( run) right down the middle of your retina (视网 膜).It creates 【小题7】 large blind spot in your visual field, but you never notice the hole it leaves. To see this blind spot 【小题8】 (clear) , try the following: cover your left eye with your hand. With your right eye, look at the 0 on the left. As you move your head 【小题9】 ( close) to the 0, the X will disappear as it enters the blind spot 【小题10】(cause) by your optical nerve. Your brain works hard to make the world look continuous!

Scientists found a prehistoric ancestor of an arrow worm (箭虫)among a group of fossils (化石)at two national parks in Canada. The fossils 【小题1】 (find) in what is now British Columbia, but was once an ocean.

The sea worm was 10 centimeters long and had 50 spines (刺)on 【小题2】 (it) head. The spines could close suddenly 【小题3】 (catch) smaller sea creatures.

The scientists say it lived 500 million years ago and is very different 【小题4】 anything alive now. Derek Briggs is a scientist from Yale University. He led 【小题5】 research. He said the creature 【小题6】 (be) larger than today's similar worms. The arrow worms of today have teeth instead of spines.

Briggs said the worm was 【小题7】(probable) a good hunter because it had so many spines. The scientists said it is difficult to find evidence of these prehistoric worms because their bodies decayed (腐烂)so quickly. But this 【小题8】 (discover) was in such good shape, so they were able to make a good guess about how the worm looked.

Researchers were able to make a 【小题9】 (detail) drawing of how they think the worm moved in the ocean. Doug Erwin works for the Smithsonian Institution in Washington, D. C. He was not involved in the research. He said the breakthrough will help scientists 【小题10】(well) understand the worms and other life from this ancient period than before.