请概括给定材料的主要内容，要求：简明扼要，条理清晰。

随着击实功的减小，土的最大干密度ρd及最佳含水率ωop将发生的变化是（）

A.ρd增大，ωoｐ减小

B.ρd减小，ωoｐ增大

C.ρd增大，ωop增大

D.ρd减小．ωop减小

有一个专题旅游团欲沿着长江考察，请回答下列问题：

苗族主要分布在长江沿岸的哪些省市区。

下列对不可抗力发生后，合同责任的描述，错误的是( )。

A．承包人的人员伤亡由发包人负责
B．工程修复费用由发包人承担
C．承包人的停工损失由承包人承担
D．发包人的人员伤亡由发包人负责

如果让你对学生讲述“每假借于藏书之家”这句话，以下讲解角度不正确的一项是（）。

A.让学生在翻译时注意此句中的“假”和“腰白玉之环”中的“腰”一样，都是名词活用为动词

B.要向学生指明“假借”是同义复合词，“假”和“借”都理解为“借”

C.可将“每假借于藏书之家”中的“之”和“走送之”“当余之从师也”“无鲜肥滋味之享”“弗之怠”几句中的“之”放在一起讲解，加深学生对“之”的几种用法的理解

D.要让学生明确这是一个倒装句，原句应是“每于藏书之家假借”

The idea of test-tube babies may make you either delighted at the wonders of modern 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 "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). 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 (输卵管). 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 is the author’s attitude toward the idea of test-tube babies().

A. Optimistic.

B. Pessimistic.

C. Delighted.

D. Irritated.