题目内容：

    It was a Saturday evening in March，just before sundown，when we heard the screaming. I was out walking with my wife，Melissa，and our golden retriever(猎犬)，Kira，beside a lake when the peace was broken by a woman’s voice，calling out two names over and over.

We spotted her，almost immediately，three or four hundred feet away across the lake. Spring had come but there was still snow on the ground，the water covered by a layer of ice that had just started to thaw. Two big dogs were walking across it. They appeared to be quite old and were moving slowly. As we watched，the ice gave way beneath one dog and then the other，plunging them into the water.

We arrived at the scene a few minutes later，but the dogs already seemed to be showing the effects of the cold as they struggled weakly to escape. We realized that calling 911 would be useless—the dog farther out was in water about 20 feet deep and I feared neither of them would stay afloat long enough for the emergency services to arrive. Besides，I was probably qualified to carry out the rescue myself. I was practicing the kind of deep breathing my grandfather had taught me as I walked in. I wasn’t alone—Kira swam alongside me. Having Kira there was a huge support. We were able to go back to shore quickly.

The second dog was further out and I had to pause before I went back in. That’s when another technique I’d learned from my grandfather came into play. He’d taught me about a pressure point on the wrist that when pressed in the right way sends out an electrical signal，like a jolt of energy. That kept me warm as I set out again with，Kira. I maintained eye contact with the dog as we approached. With Kira’s encouragement，it followed us back. The owner was emotional—“I’m the luckiest woman alive!”she said.

1.What does the underlined word“thaw”in Paragraph 2 probably mean?

A.Melt. B.Shake.

C.Flow. D.Appear.

2.Why didn’t the writer call 911?

A.The writer’s dog has been trained to save lives.

B.The dogs could save themselves from the cold water.

C.There wasn’t enough time to wait for the emergency services.

D.The writer’s grandfather had taught him how to save the dogs.

3.What do we know about the second technique the writer learned from his grandfather?

A.It makes him brave. B.It keeps him warm.

C.It allows him stay focused. D.It helps him walk quickly.

4.Who accompanied and helped the writer while saving the dogs in the water?

A.His wife. B.The dogs’owner.

C.His grandfather. D.His dog.