A:①②
B:①③
C:①④
D:②④
{an}是首项a1=1,公差d=3的等差数列,如果an=2005,则序号n等于 ( )
STUDY ENGLISH IN AMERICA
Country
Tina comes from ____.
Weekend Activity
Tina visits____ on Sundays.
Location
Tina's host family is in a ____ area.
TV Program
Tina always watches ____ in the evening.
Study Time
Stay for ____ and study English as Tina does!
下列变异现象中不能遗传的是( )