不具有细胞膜的是( )
A：小麦
B：玉米
C：细菌
D：HIV
——This is story I've told you about several times.——It's great. I've never heard more moving one.
阅读下图，选择正确答案．科学家经过精确测量，得到有关地球的数据是（ ）
