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【单选题】
证明DNA是遗传物质的第一个实验证据是“肺炎双球菌的转化实验”，肺炎双球菌有两种类型，无膜R型细菌不能使发病；有膜S型细菌使得败血症而死亡。下列哪一项叙述不能证明DNA是遗传物质（）A.
用S型细菌给注射，死亡；用R型细菌给注射，不死亡
B.
用S型细菌DNA与活R型细菌混合注射，死亡
C.
加热杀死S型细菌与活R型细菌混合注射到体内，死亡
D.
用DNA酶处理S型细菌DNA后与R型细菌混合注射到体内，不死亡
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【单选题】“ 人总是要死的” 谓词公式表示为 。（论域为全总个体域） M(x) ： x是人；Mortal(x) ：x 是要死的。
A.
M(x) →Mortal(x)
B.
M(x)∧Mortal(x)
C.
(∀ x) (M (x)→Mortal(x))
D.
(∃ x) (M (x)∧Mortal(x))
【单选题】( )4.How long has the bike been part of Thomas’ life?
A.
Since January
B.
Since last year.
C.
For a month.
D.
For a year.
【单选题】Conversation 2 6
A.
Going to the high street.
B.
Visiting everyday shops.
C.
Visiting shops and buying online.
D.
Buying things like electrical goods.
【单选题】How long does the Grand Slam tournaments, Wimbledon , last?
A.
One week.
B.
Two weeks.
C.
One month.
D.
Ten days.
【单选题】How long will it take for the panels to pay for themselves?
A.
It will take 50 years.
B.
It will take 5 years.
C.
It will take 500 years.
【单选题】How long had Valentine been executed when Lupercalia was renamed?
A.
270 years.
B.
496 years.
C.
226 years.
D.
220 years.
【单选题】Conversation 2 6
A.
Getting some celebrity endorsements.
B.
Inventing some fashionable products.
C.
Putting up some fascinating ads.
D.
Setting up activities for youngsters.
【单选题】We know from the passage that ______. ( )
A.
exposure to even tiny amounts of radiation is fatal
B.
the effect of exposure to radiation is slow in coming
C.
radiation is avoidable in space exploration
D.
astronauts in spacesuits needn't worry about radiation damage
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