题目内容
33、So often ______ in recent years that it has almost become a rule.
A. has this happened B. this has happened
C. is this happening D. for this to happen
试题答案
33、A
--How did you do in the test?
--Not so well. I _____ much better but I misread the directions for Part D.
A. could do B. could have done C. must have done D. should do
查看习题详情和答案>>---What can I do for you？---Well，I'm afraid the box is heavy for you，but thank you all the same．
A． so B． much C． very D． too
查看习题详情和答案>>_____ at the news that I didn't know what to say to comfort her.
A. So sad she looked B. So sad did she look C. So sadly she looked D. So sadly did she look
查看习题详情和答案>>I was advised to arrange for insurance _____ I needed medical treatment.
A. although B. incase C. so that D. if only
查看习题详情和答案>>分析有关遗传病的资料，回答问题。（10分）
Ⅰ、图1是具有两种遗传病的家族系谱图，设甲病显性基因为A，隐性基因为a；乙病显性基因为B，隐性基因为b。若II-7为纯合体，请据图回答：
1．甲病属于 遗传病，乙病属于 遗传病。
2．III-8的基因型是 。该系谱图中，属于她的旁系血亲有 。
3．III-10是纯合体的概率是 。
4、假设III-10与III-9结婚，生下正常男孩的概率是 。
II．研究表明，人的ABO血型不仅由位于第9号染色体上的IA、IB、i基因决定，还与位于第19号染色体上的H、h基因有关。在人体内，前体物质在H基因的作用下形成H物质，而hh的人不能把前体物质转变成H物质。H物质在IA基因的作用下，形成凝集原A；H物质在IB基因的作用下形成凝集原B；而ii的人不能转变H物质。其原理如上图2所示。
5．根据上述原理，血型为B型的人应该具有 基因和 基因。
6．某家系的系谱图如上图3所示。Ⅱ－2的基因型为 hhIBi，那么Ⅲ－2的基因型是 。
7．一对基因型为HhIAi和HhIBi的夫妇，生血型表现为O型血孩子的几率是 。