题目内容：

The sixth mass extinction of life on the Earth is unfolding more quickly than feared, scientists have warned. More than 30 percent of animals with a backbone — fish, birds, amphibians, reptiles and mammals — are declining in both range and population, according to the first comprehensive analysis of these trends.

Around a decade ago, experts feared that a new range wipeout of species was appearing. Today, most agree that it is underway — but the new study suggests that the die-out is already growing fast.

The loss of biodiversity has recently accelerated. Several species of mammals that were relatively safe one or two decades ago are now endangered, including cheetahs, lions and giraffes, the study showed.

There is no mystery as to why: our own ever-expanding species — which has more than doubled in number since 1960 to 7.4 billion — is eating, crowding and polluting its planetary cohabitants out of existence. By comparison, there are as few as 20,000 lions left in the wild, less than 7,000 cheetahs, 500 to 1,000 giant pandas.

The main drivers of wildlife decline are habitat loss, over-consumption, pollution, other species, disease, as well as hunting in the case of tigers, elephants, rhinos and other large animals prized for their body parts.

Climate change is thought to become a major threat in the coming decades, with some animals — most famously polar bears — already in decline due to rising temperatures and changing weather patterns.

1.What does the underlined word “accelerated” in Paragraph 3 mean?

A. Made up.    B. Put up.

C. Sped up.    D. Used up.

2.Why has the loss of biodiversity sped up?

A. The mankind’s population is growing fast.

B. The air pollution is too severe.

C. There are fewer species in larger areas.

D. Man causes wider water pollution.

3.Which is not the main driver of wildlife decline?

A. Outside animals.

B. Loss of living areas.

C. Various illnesses.

D. Lack of water.

4.How is the future of polar bears?

A. Uncertain.    B. Hopeful.

C. Doubtful.    D. Unsatisfying.