题目

下面是学生在实验中遇到的一些问题，其中正确的思路是（   ） A . 在进行对花生子叶的脂肪染色时，若发现整个视野范围都呈现橘黄色时，可用盐酸洗去浮色 B . 在用纸层析法分离叶绿体中色素的实验中，若发现色素带颜色过浅，可用增加划滤液细线的次数来增加颜色 C . 在“探究细胞大小与物质运输效率的关系”实验中，琼脂块中变红的体积与整个琼脂块的体积之比越大，表示物质运输效率越低 D . 在测定酵母菌的无氧呼吸产物时，可用酸性重 阅读理解： 　　Mary was a 911 operator(接线员)in Los Angeles．One Thursday morning, she was surprised to get a call from a young child who said, “Mom is ill, Mom is ill”, again and again．Mary hurried to find the address of the call．She called the police．In a minute, the policemen and doctors arrived at the house．They broke the door open, and they couldn't believe their eyes．The little child was so young that maybe she could not walk! She was sitting beside her mother and holding her mother's hand．Tears(眼泪)were running down her face． 　　The doctor gave the woman some medicine and soon she woke up．Later, she told people, “Everyone was surprised that my daughter could call 911．One Monday I tried to teach her how to call 911．” “It's the first time I’ve seen a two-year-old child call 911．” (1) What did Mary do every day? ________． [　　] A． She answered the telephone calls． B． She talked with the policemen and the doctors． C． She played with the children． D． She dealt with emergencies(紧急情况)． (2) How did she feel when she answered the little girl's call? ________． [　　] A． She was worried． B． She was sorry． C． She was surprised． D． She was happy． (3) How did the police and the doctors get into the house? ________． [　　] A． They went in through the windows． B． They broke the door open． C． They didn't go in． D． The woman was outside．They didn't need to go in． (4) How could the little girl learn to call 911? ________． [　　] A． She learnt it by herself． B． She called it by chance．(偶然地) C． Her mother taught her one Monday D． Her mother often taught her． (5) How old was the little girl? ________． [　　] A． Only two． B． She was nine． C． She was five． D． She couldn't walk, so she must be less one．