题干

下图是用显微镜观察植物细胞的叶绿体实验中的两个视野,要把视野中的物像从甲图转为乙图,下列操作步骤正确的排序是(   )
甲图         乙图
 

①转动细准焦螺旋  ②转动粗准焦螺旋③移动装片 ④调节光圈(或转换反光镜)⑤转动转换器    

A:③一⑤一②一①

B:④一③一②一⑤

C:③一①一④一⑤

D:③一⑤一④一① 

上一题 下一题 0.0难度 选择题 更新时间:2020-01-03 03:45:06

答案(点此获取答案解析)

D

同类题3

阅读下面短文,从短文后各题所给的四个选项(A、B、C和D)中选出可以填入空白处的最佳选项,并在答题卡上将该项涂黑。

    In winter, I often walk in a nearby park during lunch time. The park is quiet, as 1 people have the time to enjoy the winter sun on a weekday. The two people that are often seen are a middle-aged father and his little daughter 2 her school uniform. The father looks like he has all the time in the world-he 3to hurry along the jogging path; instead he matches his pace with 4of the little girl. Sometimes they are lying 5in the sun, laughing and chatting.

    The man certainly doesn't look6 . What sort of job can he have that gives him the flexibility to walk in the park in the middle of the day?

    And today, we 7 sat on the rocks and had a little chat. “You 8enjoy the park very much to come here so often,” I said. The father nodded. “How” I asked curiously, “do you 9 to leave your office to be with your daughter every day?”

    The story that the father, Satyendra Dugbey, told me showed me how, if we 10 under the surface, even ordinary people's life can be quite 11 .

    “I used to be no different from any of those thousands of office workers 12 to work every day,” he began. His wife and he were well 13 but rarely managed time off for leisure.

    Everything changed after an accident 14 Dugbey was hit by a car. As he lay in hospital, terrifying thoughts 15 his mind. “How would my daughter, then only four, remember me if I died that day?” “Would my daughter have 16 of being with her father?”

    The moment he recovered and went back to work, Dugbey took time off at lunch, 17 her daughter from school which was just next door to his working place, and took her to the park.

    It was actually a very small change he'd made, he said, but it amazed him every day to see the difference it 18 to his life. “It brings me so much 19 that I can't believe why others haven't thought of doing the same thing.” he said simply.

    I got up to continue my 20 walk, unexpectedly happy after his story.

同类题4

根据短文内容的理解,选择正确答案。

    As Rosalie Warren stood at the mailbox in the lobby of her apartment building in May 1980, she shared the anxiety of many other college seniors. In her hand was an envelope containing her final grades. As she nervously opened it, Warren wondered whether her hundreds of hours of studying had paid off.

    They had.

    "I got five A's," she still recalls with elation. "I almost fell on the floor!"

    Warren would graduate from Suffolk University with a Bachelor of Science degree in philosophy and history at age 80. Three years later, at age 83; she would receive her second degree from Suffolk, a master's in education.

    Now, with both diplomas proudly displayed in her apartment, Warren is not finished with learning. Now 93, she continues for her 18th year at Suffolk under a program that allows persons 65 and over to attend classes tuition free. "It's my life to go to school, to enjoy being in an academic atmosphere," she says. "That's what I love."

    Warren was born Rosalie Levey on Aug.29, 1900. Two years after she entered high school, her father died. Warren had to leave school for factory work to help support her family's 10 children. Warren describes herself as a "person who always liked school," and she says the move "broke my heart completely because I couldn't finish high school."

    In the end, however, "I went to school nights," she recalls. "Any place I could find an outlet of learning and teaching, I was there."

    A short time later, her mother became ill, and Warren had to care for her, once again putting her education on hold.

    Finally, in 1921, her mother, now recovered, drew from her saving to send Warren to Boston University for two years to study typing, stenography, and office procedures.

    Those courses helped Warren gain several long-term office positions over the next 60 years, but her great desire "to be in the academic field" continued.

    In 1924, she married Eugene Warren, and seven years later, her daughter, Corinne, was born. In 1955, by then a widow and a grandmother, Warren took a bus tour across the United States that was to last nine months. She said she wanted to see "things you never see in the West End."

    When she returned home, she took a bookkeeping position and also enrolled in courses in philosophy, sociology and Chinese history.

    In 1975, when she was 75, Warren learned from a neighbor about Suffolk University's tuition-free program for senior citizens." I was at the registrar's office the very next day," she recalls. At first, she took one or two courses at a time, but encouraged by her professors, she enrolled as a degree candidate.

    "I had not studied for so many years," she says, "but I was determined." For the next four years, Warren, who calls herself a "student of philosophy," worked toward her degree.

    Nancy Stoll, dean of students at Suffolk, says Warren is "an interesting role model for our younger students—that learning is a lifetime activity...She is genuinely enthusiastic about being here, and that permeates (散发) her activities and is contagious (传染的) to students and faculty."