【正确答案】 A

【答案解析】[听力原文]26-28
A guide dog is a dog especially trained to guide a blind person. Dogs chosen for such training must show good intelligence, physical fitness, and responsibility.
At the age of about fourteen months, a guide dog begins an intensive course that lasts from three to five months. It becomes accustomed to the leather harness and stiff leather handle it will wear when guiding its blind owner. The dog learns to watch traffic and to cross streets safely. It also learns to obey its owner's commands.
The most important part of the training course is a four - week program in which the guide dog and its future owner learn to work together. However, many blind people are unsuited by personality to work dogs. Only about a tenth of the blind find a guide dog useful.
26. How long does the intensive course last?

[详细解答] 第二段第二句提到“At the age of about fourteen months，a guide dog begins an intensive course that lasts from three to five months．”由此知训练持续三至五个月。

【正确答案】 D

【答案解析】[听力原文]
Which of the following skills guide dogs have to learn is not mentioned?

[详细解答] 见第二段最后一句，“The dog learns to watch traffic and to cross streets safely．It also learns to obey…”答案A. Watch traffic，B. Obey commands，C. Cross streets，safely都提到过。只有D. 是文中没有提到的。

【正确答案】 C

【答案解析】[听力原文]
How long does the most important training course last?

[详细解答] 见第三段第一句，“The most important part of the training course is a four-week program”，由此可知，最重要的训练课程持续四个星期。