EcoRI和SmaⅠ限制酶识别的序列均由6个核苷酸组成,但切割后产生的结果不同,其识别序列和切割点(图中箭头处)分别如下图所示,请据图分析正确的是所有限制酶的识别位点均由6个核苷酸序列组成B.SmaⅠ限制酶切割后产生的是黏性末端C.用T4DNA连接酶连接平末端和黏性末端的连接效率一样D.细菌细胞内限制酶可以切割外源DNA,防止外源DNA入侵
I think this piece of music sounds _______ than the song sung by Jay Chou.( )
more exiting
more excited
excited
exciting
-Don't be late for school again, _________?
-Sorry, I won't( )
are you
do you
will you
did you
What did the doctor say?
He warned me _______ too much meat.( )
not eat
not to eat
eat
to eat
-Does your brother often learn English _______ listening to the radio?
- Yes. And he also has conversations with his classmates ________ English.( )
by; by
in; by
with; in
by; in
-Have you seen_________ play, Mary?
Yes, it's quite ______ excellent play, so I can't wait to turn on the TV when I get home.( )
a; the
the; an
a; an
the; the