下面左图为巴西兰索玛朗汉斯国家公园每年雨季出现的“白沙碧水”奇观（照片是面向北方拍摄的被白色沙丘围绕的淡水湖泊群），此地位于该国东北部的某河河口附近。右图是该地区降水资料，河口附近的白沙受定向风吹拂形成新月型沙丘，该风是（    ）

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     Linda was a sixteen-year-old girl in Canada. She was feeling bad for several days. Her mother took her to a hospital and the doctors found out that she had cancer.

     Linda's life changed. She began to go to the hospital often for treatment（治疗）, and she also became depressed.

     The hospitals and the doctors were good, but Linda did not have hope herself. Linda's mother called a flower shop close to the hospital. “I want some beautiful flowers for my daughter. She is a teen girl with cancer.” She told the shop owner.

     Later, the flowers arrived. Then Linda saw something unusual. It was a card. It read:Linda, I own (拥有) this flower shop. I had cancer when I was fifteen years old. I am 24 years old now. Good luck. My heart goes out to you.

                                                                              Yours,

                                                                               Alice

     Linda smiled. She finally felt some real hope. She found the will (意志) to 1ive.

     Little things make a big difference. All of us can give little things like kindness, encouragement and hope to others.

动物细胞分裂时，____ 先分裂为两个，然后____ 分裂成两份，最后细胞膜向内凹陷形成两个细胞。