题目内容：

    If you think about the countless number of animal species on our planet, the giraffe is perhaps one of the most interesting. With its unusual pattern and incredibly long neck, it looks like no other animal on Earth. But how did this mammal come to get its famously huge neck? Well, scientists have been asking themselves this question for centuries.

The most commonly believed answer is that the massive neck — which measures on average 180 centimeters and weighs about 270 kilograms — evolved to allow the animal to reach the leaves of tall trees.

British scientist Charles Darwin was one of the first people to propose this idea in the 1800s.“The giraffe… has its whole frame beautifully adapted for browsing on the higher branches of trees,”he wrote in his famous 1859 book On the Origin of Species. It was Darwin’s belief that the giraffe once had a much shorter neck, but over time, evolution led to longer-necked giraffes being born, which in turn survived as they were able to reach the food that others couldn’t. Yet, there are other theories. According to a paper published in September in the Journal of Arid Environments, the giraffe’s neck evolved to increase its surface-area-to-volume ratio. Because the animal’s neck increases its body’s surface area, it makes it easier for it to keep cool, the paper’s authors wrote. This phenomenon can be seen everywhere in nature, and even in engineering.

For example, this is why elephants have such large ears, and why radiators (暖气片) in homes are flat and thin, as a large surface area allows heat to escape quicker.

Meanwhile, some believe that competition is the answer. A 1996 study by two South African zoologists argued that the male giraffes with the biggest necks are the ones who “win” access to females to reproduce, as they are better at fighting, meaning that their long necks are passed down through the generations. So, it seems like there’s still no definite answer to the question. But until we find the truth, we should at least enjoy this beautiful and interesting creature for what it is today, rather than wonder about where it came from.

1.What idea did Charles Darwin put forward in his book?

A.Giraffe’s necks are 180 cm long and weigh 270 kg on average.

B.Giraffes with a long neck are better at fighting.

C.Giraffes are a species that is born with a long neck.

D.Longer-necked giraffes are able to survive better.

2.What is the article mainly about?

A.Charles Darwin’s theory of evolution.

B.Different functions of the giraffe’s long neck.

C.How the giraffe manages to survive in nature.

D.Theories about why the giraffe has a huge neck.