题目内容：

    AIDS may be one of the most undesirable diseases in the world. Luckily, there is now hope for AIDS patients.

According to a recent paper published in the New England Journal of Medicine, Chinese scientists have successfully used CRISPR technology - a method of gene editing - to treat a patient with HIV. While it may not have cured the patient fully, it still represents a huge step forward in fighting the disease.

The patient was a 27-year-old Chinese man who was diagnosed with both AIDS and acute lymphoblastic leukemia (急性淋巴细胞白血病), a type of blood cancer. Despite his hopeless situation, doctors offered him a glimmer of hope: a bone marrow (骨髓) transplant to treat his cancer and an experimental treatment for his HIV.

They used this opportunity to edit the DNA in bone marrow stem cells from a donor before transplanting the cells into the patient.

Specifically, the treatment involved using the gene-editing tool CRISPR-Cas9 to delete a gene known as CCR5, which encodes a protein that HIV uses to get inside human cells. Without the gene, HIV is unable to infiltrate cells.

Talking about the gene, lead scientist Deng Hongkui told CNN, “After being edited, the cells - and the blood cells they produce - have the ability to resist HIV infection.”

Nineteen months after the treatment, the patient’s leukemia was in complete remission (缓解) and donor cells without CCR5 remained, according to the research paper.

Though the transplant did not cure the man’s HIV, it still showed the effectiveness of gene-editing technology, as there was no indication of any unintended genetic alterations - a major concern with past gene therapy experiments.

Amesh Adalja, a senior scholar at the Johns Hopkins Centre for Health Security in the United States, who was not involved in the study, praised the treatment.

“They did a very innovative experiment. It was safe,” he told Live Science. “It should be viewed as a success.”

Deng believes gene-editing technology could “bring a new dawn” to blood-related diseases such as AIDS and sickle cell anemia (镰刀形细胞性贫血).

“Thanks to this new technology, the goal of a functional cure for AIDS is getting closer and closer,” he said.

1.The technology of CRISPR is to ___________.

A.transplant cells B.encode genes

C.remove proteins D.produce cells

2.What was the result of the treatment?

A.CCR5 and other genes in the patient’s cells were changed.

B.The number of cells infected by HIV decreased.

C.Some of the patient’s blood cells could resist HIV infection.

D.HIV no longer existed in the patient’s cells.

3.What do we know about the experiment?

A.It provided an innovative way to cure AIDS patients.

B.It pointed out the problems of gene therapy.

C.It could offer a safe treatment for blood-related diseases.

D.It’s the first experiment to use gene-editing technology to treat AIDS.