染色体存在于 （ ）中
A：细胞质
B：细胞膜
C：细胞核
D：液泡
长江中游沿江地带的钢铁工业基地是以下列哪个城市为中心的：（ ）
Look at this desk. It's Jim's desk. It's brown. Jim's book is on it. The book is his English book. His pencil-box is on it, too. His pencil is in his pencil-box. But where's his pen? He can't find(找到) it.
读图“地球经纬网图”，完成下列问题。
