题干

下列能正确表示高等动物胚胎发育顺序的是(     )

A:受精卵→囊胚→桑椹胚→原肠胚→幼体

B:卵→桑椹胚→原肠胚→囊胚→幼体

C:卵→囊胚→桑椹胚→原肠胚→幼体

D:受精卵→桑椹胚→囊胚—原肠胚→幼体

上一题 下一题 0.0难度 选择题 更新时间:2019-06-24 11:03:42

答案(点此获取答案解析)

D

同类题2

信息归纳:阅读下文,根据所提供的信息,完成下列表格。

    Your Junior 3 year will finish soon. Do you want to say something about your junior school life? What were the rewards (收获) of the three years? Our readers have their stories to share.

Ben,15,Guangzhou,Guangdong

   I experienced a hard time in Junior 2 when my grades suddenly dropped(下降) a lot. I faced great pressure. In the following summer vacation, I worked hard by studying for 10 hours a day. It was crazy, but when I became one of the top students again, I felt everything had been worthwhile(值得的).

Julie, 13,Beijing

     In July, 2011,I had a trip to the UK with some students and teachers. When we arrived there, the other students and I didn't want to eat the local food. The teachers were worried and tried to make us eat. When we finally finished the meal, the guide said that the world now sees how spoiled(被宠坏的)Chinese kids are. I felt really sorry.

John,14,Hangzhou,Zhejiang

    I lived in a dorm(寝室)during junior school. It was a great challenge since I had never left my parents before that. I had to take care of everything myself. I learned to make my bed and get along with roommates. I also learned to make a schedule to arrange(安排)my time .I've done a good job and I feel proud.


Information Card

Age of Ben

____

Place John is from

____

Time Julie went to the UK

____

How Ben improve his grades

____

Things John has learned during junior school

Make the bed ____

Make a schedule to arrange time

同类题3

阅读理解

    Are you scared about moving up to senior high school?It can be a new experience,but you shouldn't worry.We've put together a guide on how to survive the first week.

    You're not alone

    Remember everybody else in your year is in the same boat.They may not realize it,but they're just as nervous as you are.Moving to senior high is an opportunity,not a problem.Things are different and all you need to do is be polite and learn the new rules.

    Teachers are ready to help!

    If you're unsure what to do or are worried about anything then you had better ask for help.Teachers are probably the best people to turn to as they're experienced in helping new students.Some senior high schools also have a “friends system”.If your school has this,then you will be paired with an older student.They will look out for you and help you if you have any problems or questions.

    All change

    There are lots of differences between junior high school and senior high school.You'll have a homework diary or a student planner.You will have your lessons with different teachers in different rooms.You will have homework for different subjects on different days,so make sure you get organized.Make sure you have a copy of your school timetable written down so you know which rooms your classes are in and on which days you will have your different subjects.

Other points

    If you've got an older brother or sister at the school then ask them for advice.

    Be yourself! It sounds simple,but people will know you much better if you just act naturally.

    Having early nights makes a difference and you'll find it easier to get up in the morning!