题目

化学与我们生活密切相关，日常生活中的化学知识有很多。想想看，生活中常用的下列物质分别含有什么化学成分（填化学式）：（1）干冰常用于人工降雨。干冰中的“冰”是指            ；（2）天然气是常用的气体燃料，天然气中的“气”是指        ；（3）纯碱是生活中常用的洗涤剂，纯碱中的“碱”是指          ；（4）碘酒是常用的皮肤消毒剂，碘酒中的“碘”是指             。Not long after I started teaching at Kamiakin Junior High near Seattle, Michael, my six-month-old son, was diagnosed with elodysplastic syndrome（骨髓发育不良综合症）．It's a pre-leukemia（白血病前期） disease．He needs a bone-marrow transplant（骨髓移植）．Soon after the diagnosis, everyone in the family had a blood test in the hope that one of us would be the bone-marrow donor（捐献者）． On March 20, my wife Kristi called me at work to share some good news, "Amy is a perfect match!" As a result of the donor search, however, a dark cloud cast a shadow over our hope．The bone-marrow transplant would cost more than $200,000．We would gladly pay that to save any one of our children----but how could we pay it? The next day, Steven Mezich, Kamiakin's principal had a talk with me． "Jeff," he said, "with your permission I want to propose a fund-raiser（募捐） at this afternoon's staff meeting, to help your family．" I was surprised．Steven's thoughtful offer raised my spirits, though I doubted it could do much to help us overcome such a huge and urgent financial problem． That afternoon, Dameon Sharkey, a student from my class, walked into my office with his mom and gave me his life savings of $60 ---- all in $5 bills．And the next day after the staff meeting, we received wishes for Michael's recovery, prayers, loving support, $350 cash, and checks． The outpouring of love from these friends moved me to tears．But that’s not the end．Joe Kennedy, Kamiakin's humanities teacher, challenged the school's students to see what they could do to help Michael．These high-spirited junior-high kids immediately went to work, making plans to start a walkathon, hold a raffle（抽奖）, set up donation boxes, and attract news coverage．As a result of the students' efforts, stories appeared in The Journal American and NEW YORK TIMES．Scores of independent, unrelated efforts took place all over Seattle areas．A month after Dameon's gift opened the floodgates, Michael's fund totaled $220,000． Our baby would get a second chance! 1．What worried the author most was whether there was ______．      A．a bone-marrow donor                                 B．enough time for Michael to wait C．support from the society                             D．money to cover the cost of treatment 2．We can learn from the underlined sentence that ______．      A．the author was encouraged by Steven’s offer      B．the author was discouraged by Steven’s words      C．the author was still in despair at Steven’s words D．the author was sure that he could get over the difficulty 3．From the passage we know that Steven Mezich was ______． A．brilliant                   B．talkative                  C．helpful                    D．nosy 4．We can infer from the passage that ______．       A．Amy is the author’s daughter                       B．Michael was cured in the end       C．the students made a great contribution          D．a bone-marrow transplant costs a lot