问题 单项选择题

HBV处于复制状态,有传染性的标志是()

A.抗-HBe

B.HBcAg(+)

C.抗-HBs

D.HBsAg

E.抗-HB

答案

参考答案:D

材料分析题

想一想

       阿拉伯半岛和长江中下游地区处在大体相同的纬度位置上,但气候差别却很大。阿拉伯半岛大部分地方是炎热干燥、人迹罕至的沙漠,自然条件极为严酷。而我国的长江中下游地区则降水丰沛,山清水秀,处处鱼虾肥美,稻米飘香,是著名的“鱼米之乡”。

(1)造成这两个地区气候差异的主要原因是什么?

                                                                                                                                                              

                                                                                                                                                              

(2)我国气候的特点是什么?举例说明它对我国的生产和生活产生的影响。

                                                                                                                                                              

                                                                                                                                                              

                                                                                                                                                              

单项选择题