双脱氧核苷酸常用于DNA测序,其结构与脱氧核苷酸相似,能参与DNA的合成,且遵循碱基互补配对原则。DNA合成时,在DNA聚合酶作用下,若连接上的是双脱氧核苷酸,子链延伸终止;若连接上的是脱氧核苷酸,子链延伸继续。在人工合成体系中,有适量的序列为GTACATACATGCCGGATT的单链模板、胸腺嘧啶双脱氧核苷酸和4种脱氧核苷酸。则以该单链为模板合成出的不同长度的子链最多有( )
Why is Grace's Chinese so good?
Because she China for ten years.( )
has gone to
has been to
has come to
has been in
Paper is useful invention.Cai Lun invented it around 2,000 years ago.( )
a
an
the
不填
Excuse me, could you tell me _______?
Go along this road to the bus station, and take Bus No. 31.( )
where is the Rice Museum
which the way to the Rice Museum was
how I can get to the Rice Museum
whether is the Rice Museum near here
A landmark(里程碑) in the history of science was made by a photo _______ was taken on April 10th about the black hole in a faraway galaxy(星系).( )
who
which
what
when
Our life _______ greatly by 3D printing technology in a few years.( )
will influence
influences
will be influenced
is influenced