Although similar in appearance to hyenas(土狼), African wild dogs are nevertheless true wild canine(犬). They are a mixture of black, yellow, and white in such a wide variety of patterns that no two individuals look exactly alike. African wild dogs are widely distributed across the African plains but they do not live in jungle areas.
They are social animals, living in groups of usually from 2 to 45 individuals. A hierarchy（统团） exists within the group, but the animals are friendly to one another. The young and the infirm（体弱的） are given special privileges within the group.
African wild dogs use their sense of sight, not smell, to find their prey. They can run up to 55 km/h for several kilometers. In eastern Africa, they mostly hunt Thomson's gazelles, but they will also attack calves, warthogs, zebras, impalas, and the young of large antelopes such as the gnu.
Growing human populations have decreased or degraded the African wild dog's habitat and also diminished their available prey. Road kill and human persecution（迫害） have also had a negative impact on African wild dog populations. This species is also susceptible to a variety of diseases such as distemper, which is controlled in domestic .dogs. Conservation of the African wild dog's natural habitat must have the highest priority, as these dogs suffer in habitats modified by human intrusion（干扰）．
小题1:What does the underlined word "susceptible" mean?
A．easily affected or suffered
B．badly doubtful
C．seriously harmful
D．highly dangerous小题2:What factors affect the population of the wild dogs?
a. the distribution of the dogs b. social living
c. highly increasing human populations d. human's killing the dogs
e. many diseases f. the changes of their habitats
g. domestic dogs h. food reduction
A．a. b, c, d, e
B．b, c, d, e, f
C．c, d, e, f, h
D．d, e, f, g, h小题3:From the passage we can conclude that_______.
A．African wild dogs are completely different from domestic dogs in size, weight
B．African wild dogs are living in groups
C．African wild dogs use their eyes mostly when sleeping to guard
D．African wild dogs use their noses to find their food in most cases小题4:What can we know about African wild dogs?
A．In a pack there may be about 90 wild dogs and no leader.
B．There are no such wild dogs that are different.
C．African wild dogs can run at a speed of about 15 m/s for a long distance.
D．All African wild dogs kill zebras, impalas, and antelopes as their food.小题5: What can we infer from the passage?
A．African wild dogs are not in danger, because there are such a wide variety of patterns.
B．African wild dogs are not in danger, because are widely distributed across the African plains.
C．African wild dogs are in danger, because human's activities have a great effect on them.
D．African wild dogs are in danger, because their habitats have been changed much.
