回答问题 完形填空2.docx

高考回答问题训练（二）Class _____________Name _____________No. _____________ ClozeDirections: For each blank in the following passage there are four words or phrases marked A, B, C and D. Fill in each blank with the word or phrase that best fits the context.Prince Harry of Wales, Scottish actress Karen Gillan, Ron Weasley from the movie Harry Potter—what do they have 51 ? They all have ginger hair, or as people usually say, they are all “redheads”.Britain may be the most red-headed country in the world. About 1 to 2 percent of the world’s population has red hair, but in the UK the numbers are much 52 , with 13 percent of Scots, 10 percent of the Irish, and 6 percent of people in England having red hair.Scientists have tried to explain why some people have red hair for some time and now they may have found an answer: the dull 53 in Britain.“I think it’s to do with sunshine,” said Alistair Moffat, the headmaster of St Andrews University, UK. The human body needs vitamin D from 54 , but unfortunately people living in Britain do not have enough of it because of its marine climate. 55 , Britain gets even more cloud than countries in the far north of Europe. In Sweden, for example, the average daily hours of sunshine is 5.4. In Scotland it is only 3.1 hours.To 56 this, the DNA of people living in these areas has changed 57 ; scientists call this a mutation (变异). Originally, the 58 on our body is a mixture of two kinds of melanin (黑色素)—black melanin and red/yellow melanin, but with certain parts of DNA 59 , the production of black melanin is restricted while only red/yellow melanin is made. The 60 is red hair, light skin color, freckles (雀斑) and a greater 61 to sunlight.“We need 62 skin to get as much vitamin D from the sun as possible,” added Moffat. 63 , what’s more interesting is that the redhead DNA mutation is recessive, which means it is hidden and can often 64 generations without showing.“At least 1.6 million Scots carry a red-head gene mutation, and most