阅读理解。 As an experienced photojournalist in Nashville, Tennessee, I was hired by USA Today newspaper to photograph a spinal bifida (脊柱畸形) corrective surgical procedure. It was to be performed on a twenty-one week old fetus (胎儿)in uterus (子宫)at Vanderbilt University Medical Center. At that time, in 1999, twenty-one weeks in uterus was the earliest that the surgical team would consider for surgery. The worst possible outcome would be that the surgery would cause premature delivery, and no child born earlier than twenty-three weeks had survived. The tension could be felt in the operating room as the surgery began. A typical C-section incision (切口) was made to access the uterus, which was then lifted out and laid at the junction of the mother's thighs (大腿). The entire procedure would take place within the uterus, and no part of the child was to breach the surgical opening. During the procedure, the position of the fetus was adjusted by gently manipulating ( 熟练 操作) the outside of the uterus. The entire surgical procedure on the child was completed in one hour and thirteen minutes. When it was over, the surgical team breathed a sigh of relief, as did I. As a doctor asked me what speed of film I was using, out of the corner of my eye I saw the uterus shake, but no one's hands were near it. It was shaking from within. Suddenly, an entire arm thrust out of the opening, then pulled back until just a little hand was showing. The doctor reached over and lifted the hand, which reacted and squeezed the doctor's finger. As if testing for strength, the doctor shook the tiny fist. Samuel held firm. I took the picture! Wow! It happened so fast that the nurse standing next to me asked, 'What happened?' 'The child reached out,' I said. 'Oh. They do that all the time,' she responded. The surgical opening to the uterus was closed and the uterus was then put back into the mother and the C-section opening was closed. It was ten days before I knew if the picture was even in focus. To ensure no digital manipulation of images before they see them, USA Today requires that film be submitted (提交) unprocessed. When the photo editor finally phoned me he said, 'It's the most incredible picture I've ever seen.' 1. In 1999, people believed that it was ______. A. possible for a fetus 21 weeks born to survive B. likely for a fetus born 21 weeks to become deformed (畸形的) C. right time for a fetus born 21 weeks to receive an operation D. risky for a fetus 21 weeks in uterus to receive an operation 2. From the second paragraph, we can see that the surgery was ______. A. challenging but successful B. demanding and unsuccessful C. simple and short D. long-lasting and difficult 3. The underlined'It' in paragraph 3 refers to ______. A. the shaking of the uterus B. the arm of the fetus C. the taking of the picture D. the head of the fetus 4. From the editor said in the last paragraph, we know the photo editor was very ______. A. disappointed B. satisfied C. annoyed D. depressed