阅读下面短文，掌握大意，然后从1-20各题所给的四个选项（A、B、C和D）中，选出最佳答案。

        My husband, Bob, died in January 2004. His death was unexpected as well. I 1 condolences(哀悼)from people I hadn't heard from in years: letters, cards, flowers, calls, and visits. I took a bad knock with 2. I was so struggling to3the whys and hows of this terrible thing that had happened to my family, knowing in my heart that there really were no 4. It's just all so sad.

        One message5me deeply. I received a letter from my best friend from sixth6 through high school. We had drifted somewhat since 7 in 1959, as she stayed in our home town and I did not. 8 it was the kind of friendship that could quickly resume even if we9touch for five or ten years.

        Her husband, Peter, had died perhaps 20 years ago at a young age, 10her with deep sorrow and heavy 11: finding a job and raising three young children. She and Pete, 12 Bob and I, had shared one of those rare, close, "love-of-your-life-you-can-never-forget" 13.

        In her letter she 14 an anecdote about my mother who had passed away years ago. She wrote, "When Pete died, your dear mother 15me and said, 'Trudy, I don't know what to say...so I'll just say I love you.'"

        She closed her letter to me repeating my mother's words of so long16, "Bonnie, I don't know what to say...so I'll just say I love you."

        I felt I 17 almost hear my mother speaking to me now. What a 18 message of sympathy! How dear of my friend to cherish it all those years and then 19 it on to me.I love you. 20 words. A gift. A legacy(遗赠物).

下列关于世界人口的说法，不正确的是（　　）

乙同学直接加热煮沸饱和FeCl₃溶液；

丙同学向25ml沸水中逐滴加入1～2mL FeCl₃饱和溶液，继续煮沸至液体呈红褐色，停止加热．

试回答下列问题：

阅读下面短文, 根据其内容写一篇60词左右的内容概要。

    With global warming and melting ice, it isn't easy being a polar bear anymore. Some studies have predicted that polar bears could die out by the end of the century. The good news is not all researchers think the bears are absolutely disappearing. Scientists at the American Museum of Natural History(AMNH) have published a new paper indicating that things might not be as bad for polar bears as some scientists expect.

    To understand the reason for the researchers' cautious optimism, we must first understand the factors that are threatening the polar bear's existence. Polar bears consume a diet of mainly young seals. In order to hunt these seals, polar bears need to rest at the top of sea ice---the same ice that is increasingly melting for most of the year thanks to climate change. In another 50 years, experts expect that the Arctic will be too warm for sea ice to form for half of the year, leaving polar bears without a reliable food source and in serious danger of starvation.

    As it turns out, alternative food sources for the polar bears aren't completely out of the question. For as long as biologists have tailed after the animals, they've seen polar bears eating animals found on land like caribou(驯鹿) and snow geese---as well as the snow geese's eggs.

    Can polar bears actually survive off these alternative food sources for long periods of time? To figure this out, researchers calculated the nutrients that a caribou and snow geese diet would provide. They found that even adult male polar bears would be able to obtain more calories than would burn in hunting these meals. Moreover, the food would provide the food lecessary to avoid starvation during the summer months.

    Unfortunately, not all polar bears have tended to seek food on land. That said, the researchers expect that necessity would push more polar bears to hunt on land to avoid starvation. They also expect that the bears could learn from their fellow bears how to hunt on land until the practice becomes second nature.