题目内容
Sunshine Park is a beautiful place ________ a big lake and many trees.| A．has | B． have | C．there is | D．with |
略
培优好卷单元加期末卷系列答案It is easy for us to tell who our family members are, but do plants recognize(识别) their own family? Some do, scientists say, according to a report by Science News in early 2010.
Guillermo P. Murphy and Susan Dudley are two plant scientists from McMaster University in Hamilton, Canada. They did a few experiments with Jewelweeds, a kind of flower that grows in wet, shady spots. They found that the flowers seem to know their own flower family. In their experiments, Murphy and Dudley planted jewelweeds in pots with either siblings or strangers.
When jewelweeds were planted in pots with strangers, the plants started to grow more leaves than if they had been planted alone. This response(反应)suggests that plants are competing with strangers for sunlight, since a plant with more leaves can receive more light and make more food. Jewelweeds usually grow in the shade, where sunlight is not enough.
When jewelweed seedlings(幼苗)were planted with siblings, they grew a few more branches than they usually would if they were alone – but they did not start growing lots of extra leaves. This behavior suggests the plants are more likely to share resources, rather than compete.
According to the Science News report, Jewelweeds are not the first plants that plant scientists have studied for family recognition. In 2007, Dudley and her team studied the Great Lakes sea rocket, a plant that grows on the beach – where it may be hard to get fresh water. In that experiment, the scientists found that when sea rockets were planted with siblings, they tolerated each other. But when they were planted with strangers, the sea rockets reacted by working extra hard to grow lots of roots.
Dudley says this just because sea rockets, on the beach, get plenty of sun but struggle for water – so when they’re threatened, they compete for water. Jewelweeds have plenty of water but have to compete for sunshine, so they grow more leaves.
【小题1】 What does the underlined word siblings mean?
| A．Flowers come from foreign countries. |
| B．Plants growing in different environments. |
| C．Flowers planted with lots of strangers. |
| D．Plants that are the same kind. |
| A．make a comparison | B．introduce a topic |
| C．describe a pretty flower | D．build a new theory |
| A．grow more leaves than those planted in groups |
| B．become taller than those with more branches |
| C．grow fewer leaves than those planted with strangers |
| D．become ill easily because they can’t get enough shade |
| A．New Discoveries about Plants |
| B．How Plants Compete with Each Other |
| C．Family Recognition among Plants |
| D．Jewelweeds and the Great Lakes Sea Rockets |
Suppose you are a football fan and have to work from 9:00a.m. to 5:00 p.m. on weekdays. Now you are reading the TV guide online of Sunshine Town TV(STTV) and looking through the TV programmes of Wednesday, November 21,2012.
| TV Channel | TV Programmes Wednesday, November 21,2012 |
| STTV－1 | 14:05 TV Play: Come Back Home 16:05 A Glimpse(一瞥) of London 18:10 35－part Series: Love for the Pearl River 19:50 Approaches to Science 20:10 News STTV English Service 20:40 The World Football Cup (France vs. England) |
| STTV－2 | 14:30 The World Football Cup (America vs. Italy) 16:30 TV Play: True Feeling 19:00 Children’s Programmes 19:30 Animal World 20:00 Countryside Life 21:00 American Professional Basketball Matches |
| STTV－3 | 14:15 Sports Programmes (Cycling) 16:20 Science Age 19:00 Music Bridge 19:35 Film: Gone with the Wind 21:00 Chinese Programmes for Foreigners 22:03 TV Theaters |
| A．STTV－1 The World Football Cup (France vs. England) |
| B．STTV－2 The World Football Cup (America vs. Italy) |
| C．STTV－3 Sports Programmes (Cycling) |
| D．STTV－2 American Professional Basketball Matches |
| A．STTV－1 | B．STTV－2 | C．STTV－3 | D．None of the above |
| A．Approaches to Science | B．Film: Gone with the Wind |
| C．Countryside Life | D．35－part Series: Love for the Pearl River |