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the earliest answers come from australia, where a group of medical experts at the queen victoria medical center in melbourne have taken a look at the continent"s first nine successful " in vitro pregnancies. the australians report that the pregnancies themselves seemed to proceed according to plan, but at birth some unusual trends did show up. seven of the nine babies turned out to be girls. six of the nine were delivered by caesarean section ( 剖腹产手术 ) . andone baby, a twin, was born with a serious heart defect and a few days later developed life-threatening problems. what does it all mean? even the doctors don"t know for sure, because the numbers are sosmall. the proportion of girls to boys is high, but until there are many more test-tube babies noone will know whether that"s something that just happened to be like that or something specialthat happens when egg meets sperm in a test tube instead of a fallopian tube. the same thing istrue of the single heart defect; it usually shows up in only 15 out of 60,000 births in that part of australia, but the fact that it occurred in one out of nine test-tube babies does not necessarilymean that they are at special risk. one thing the doctors can explain is the high number of caesareans. most of the mothers were older, had long histories of fertility problems and in some cases had had surgery on the fallopian tubes, all of which made them likely candidates forcaesareans anyway. 41. what would people be most concerned about according to the author? 42. what does the latin word "in vitro"(paragraph two) most probably mean? 43. the australian experiment of the test-tube babies has the following unusual trends except that 44. which of the following explanations regarding the high number of caesarean operations is not true? 45. what is the author"s attitude toward the idea of test-tube babies? passage 4 speaking, or socializing. almost eleven percent of the studentsaged 3-21 in this country have an impairment that affects their ability to benefit from a regulareducation program. handicapped students require special education because they are oftenmarkedly different from most children in one or more of the following ways: mentally retarded,learning-disabled, emotionally disturbed, deaf, visually handicapped, physically handicapped,or other health impairments. |
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