某学习小组对城市A不同时期的人口数量情况进行了研究，相关统计数据如图。请你帮他们分析并回答以下问题：

（1）该城市人口数量在哪段时间的自然增长率明显加快？___              _。

（2）从总体上看，该城市人口增长呈___              _趋势（填“匀速增长”或“逐渐减缓”）；出现上述变化的主要原因是我国已实施___              _这一基本国策。

（3）我国婚姻法明确规定禁止___              _，是为了减少遗传病的发生。

The medicine ___ as soon as you take it. But it ____ the blood.

A．brings into effect; effects

B．takes effect; has a bad effect on

C．comes into effect; has little effect on

D．is carried into effect; has much effect on