题目内容：

A group of swimmers has described how a group of dolphins protected them from a group of white sharks （食人鲨）off the coast of New Zealand. The lifeguards were on a training swim when they came across a group of great white sharks before the dolphins raced in to help.

The swimmers were surrounded by the dolphins for forty minutes before they were able to make them safety back to the beach. It was an uncomfortable experience as they were circled by a group of white sharks, which came within a couple of meters of them. Lifeguard Rob Howes was in the water with a colleague and his teenage daughter. He said around half a dozen dolphins suddenly appeared and forced them to gather together. The mammals swam in tight circles to create a protective wall between the white sharks and the lifeguards as the great white sharks were under the surface.

The swimmers said the dolphins were extremely upset and repeatedly slapped (拍打) the water with their tails as if to try to prevent the white sharks from attacking them. It’s a day they’ll never forget, especially for one who was on her first day as a volunteer. They have no doubt that the dolphins acted on purpose to protect them. Researchers have said that they’re not surprised. A marine biologist insisted that dolphins, which are considered to be one of the most intelligent mammals, “like to help the helpless.”

1.How many swimmers are attacked by the white sharks?

A. Two.     B. Three.    C. Four.    D. Five.

2. It seemed that the dolphins slapped the water with their tails to ____.

A. attack the white sharks and the lifeguards

B. play with water together for pleasure

C. stop the lifeguards being harmed by the sharks

D. attract the white sharks to kill the lifeguards

3.The underlined words “a volunteer” refers to____.

A. a lifeguard     B. Rob Howes’s workmate

C. Rob Howes        D. Rob Howes’s daughter

4. Which of the following can be the best title?

A. Dolphins Protect Swimmers from Sharks

B. Sharks Protect Swimmers from Dolphins

C. Lifeguards Protect Dolphins from Sharks

D. Lifeguards Protect Sharks from Dolphins