案例一：上官夫妇目前均刚过35岁，打算20年后即55岁时退休，估计夫妇俩退休后第一年的生活费用为8万元（退休后每年初从退休基金中取出当年的生活费用）。考虑到通化膨胀的因素，夫妇俩每年的生活费用预计会以年4%的速度增长。夫妇俩预计退休后还可生存25年，现在拟用20万元作为退休基金的启动资金，并计划开始每年年末投入一笔固定的资金进行退休基金的积累。夫妇俩在退休前采取较为积极的投资策略，假定年回报率为6%，退休后采取较为保守的投资策略，假定年回报率为4%。根据案例一回答71～79题（计算结果保留到整数位）
上官夫妇35岁初的20万元资金到60岁初约增值为（ ）（注：投资25年，投资收益率6%）。
A．492,187元
B．578,678元
C．858,374元
D．689,905元
参考答案：C
| The idea of test-tube babies may make you either delighted at the wonders of modem medicine or irritated while considering the moral, or legal, or technological implications-of starting life in a laboratory. But if you’ve ever been pregnant yourself, one thing is certain: You wonder what it’s like to carry a test-tube baby. Are these pregnancies normal Are the babies normal 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 invitro pregnancies. The Australians report that the pregnancies themselves seemed to have proceeded 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. And one 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 so small. The proportion of girls to boys is high, but until there are many more test-tube babies no one will know whether that’s something that just happened to be like that or something special that happens when egg meets sperm in a test tube instead of a fallopian tube. The same thing is true 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 necessarily mean 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 for Caesareans anyway. The Australian researchers report that they are quite encouraged. All the babies are now making normal progress, even the twin with the birth defects. |
What does the word "invitro" underlined in Paragraph 2 most probably mean
A．Normal.
B．Test-tube.
C．Built-in.
D．Formal.