植物细胞表现出全能性的必要条件()
A.给予适宜的营养和外界条件
B.导入其他植物的基因
C.脱离母体的,给予适宜的营养和外界条件
D.将成熟的筛管的细胞移到去核的卵细胞
参考答案:C
设等比数列{an}的前n项和为Sn,a4=a1-9,a5,a3,a4成等差数列.
(1)求数列{an}的通项公式,
(2)证明:对任意k∈N+,Sk+2,Sk,Sk+1成等差数列.
At the meeting, Doctor Li thought of lots of ways to solve the air pollution.[ ]
A. paid attention to
B. put up with
C. catch up with
D. came up with