The tickbird and the giraffe have a connection relationship that some scientists describe as win-win relationship and some as parasitism (寄生). This interspecies partnership is imbalanced in favor of the giraffe because it can live without the tickbird, while the tickbird is dependent on the giraffe for food resource.
The giraffe is a large mammal that lives in Africa along with other large grass-eaters. All these and many others host the tickbird. This bird has long been thought to remove ticks (扁虱) from its host, to the benefit of both—the bird eats the ticks, and the host is relieved of blood-sucking, disease-carrying insects—but recent studies reveal that this process is less than good. A secondary benefit to a host from the tickbirds’ presence is a sort of early warning system, since the birds make a loud sound if they sight an enemy. This is of less benefit to the giraffe than to other hosts because the giraffe has the advantage of great height and keen eyesight and is fully capable of spotting predators without the bird’s assistance. The tickbird is likely of greater benefit in this capacity to the nearsighted rhino.
They cross through the host’s hair looking for insects as their food. According to the researcher Paul Weeks, reporting in the journal Behavioral Ecology, tickbirds can and do enlarge tick bites and other wounds on their host body to seek for food resource, making the host-tickbird relationship unfair. The host, like the giraffe, however, would have a hard time keeping tickbirds off itself. So they tolerate the birds who cling to their bodies and chow down selectively at the buffet on the giraffe’s body.
【小题1】Which statement about the tickbird is TRUE?
| A．It doesn’t rely on the giraffe for food. |
| B．It removes ticks from its hosts. |
| C．It makes gentle sounds when it spots an enemy. |
| D．It brings more benefit to its hosts than it gets from them. |
【小题2】Why does the giraffe benefit less than other hosts according to Paragraph 2?
| A．Because the giraffe has no tick on its body. |
| B．Because the giraffe has its own warning system. |
| C．Because the giraffe is tall and has sharp eyesight. |
| D．Because the giraffe is strong enough to protect itself. |
【小题3】The underlined phrase “cling to” can be replaced by “________”.
| A．stick to | B．lead to | C．keep away | D．hold back |
【小题4】What is the suitable title for the passage?
| A．Tickbird and Giraffe: Unequal Relationship | B．Tickbird and Giraffe: Friendly Relationship |
| C．Tickbird and Giraffe: Mysterious Relationship | D．Tickbird and Giraffe: Conflicting Relationship |
