8.Yellow is a warm colour. It can _____you of a sunny day and ______ wisdom.
A. bring; remind B. remind; make C. send; bring D. remind; bring
7. The flats in many big cities are still_____ expensive and they have brought people_____ trouble.
A. too much ;much too B. too much ; too much
C. much too; too much D. much too; much too
6. Mary ______ an article carefully when the boss went to get a CD he _____in the office.
A. typed; left B .was typing; had forgotten
C. had typed; had left D. was typing; had left
5.---You are in a hurry! What’s up?
---I’m new here and I lost my way. My friend didn’t tell me________.
A. Where he lived in B. which district he lived in
C. where did he live D. which district he lived
4.---There are so many flowers on _____side of the street.
---Yes. I hope that all the flowers belong to ____
A. every; me and you B either; you and me
C. both; you and I D. each; I and you
3. ---I think they are enough. We ____make so many chairs.
---I don’t think so. Because nearly a quarter of them need______.
A. don’t need; make B. needed; to be mended
C. don’t need to; mending D. need; to mend
2. ---About _____of the village______ homeless after the big earthquake.
---Yes, we should help them rebuild the houses.
A. three fourths; was B. three-fourth; were
C. three-fourths; were D. three fourth; was
1．---____unlucky girl Du Li is! She lost ____ first golden medal in the Olympic Games.
--- What a pity! But she is still the best in my heart.
A. What a; the B. What an; the C. How a ;a D. How an; the
(三)针对整个生物界来说，绝大多数生物的遗传物质是DNA，所以DNA是主要的遗传物质。
[基础训练]1、如果用15N、32P、35S标记噬菌体后，让其侵染细菌，在产生的子代噬菌体的组成成分中，能够找到的放射性元素为( A )
A、可在DNA中找到15N和32P B、可在外壳中找到15N和35S
C、可在DNA中找到15N和32P、35S D、可在外壳中找到15N
2、下列哪项是艾弗里及其同事研究肺炎双球菌的方法或实验设计思路( D )
A、杂交实验法 B、放射性同位素标记法
C、病毒侵染法 D、单独直接观察不同成分作用
3、真核生物遗传是细胞核和细胞质共同作用的结果，控制细胞核和细胞质遗传的物质是( A )
A、DNA B、RNA C、DNA和RNA D、DNA或RNA
[高考模拟]4、(2007广东生物5)格里菲思(F. Griffith)用肺炎双球菌在小鼠身上进行了著名的转化实验，此实验结果( D )
A、证明了DNA是遗传物质 B、证明了RNA是遗传物质
C、证明了蛋白质是遗传物质 D、没有具体证明哪一种物质是遗传物质
5、(2008江苏生物8)某研究人员模拟肺炎双球菌转化实验，进行了以下4个实验：①S型菌的DNA+DNA酶→加入R型菌→注射入小鼠；②R型菌的DNA+DNA酶→加入S型菌→注射入小鼠；③R型菌+DNA酶→高温加热后冷却→加入S型菌的DNA→注射入小鼠；④S型菌+DNA酶→高温加热后冷却→加入R型菌的DNA→注射入小鼠。以上4个实验中小鼠存活的情况依次是( D )
A、存活、存活、存活、死亡 B、存活、死亡、存活、死亡
C、死亡、死亡、存活、存活 D、存活、死亡、存活、存活
(二)不具有细胞结构的生物--病毒：多数遗传物质是DNA，如T2噬菌体。少数遗传物质是RNA，如HIV病毒，SARS病毒。