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问题 问答题

一束光线经过一个透镜前后的情况如图所示，请在图中虚线框内画出这个透镜．

答案

折射光线比起入射光线更加远离主光轴，所以该透镜对光线有发散作用，因此填凹透镜．如下图所示：

单项选择题

急性毒性试验一般观察时间是（）。

A.1小时

B.1天

C.1周

D.2周

E.1月
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问答题

Lesotho Builders agreed to reconstruct a laundry and to complete the work within 10 weeks. The work took 12 weeks and the laundry is claiming damages for the loss of normal profits during the two additional weeks and also for the loss of a particularly valuable contract which it could not accept because its machines were out of action.Required:Advise Lesotho Builders as to their liability for breach of contract. (10 marks)
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