下列关于人体生命活动调节过程的叙述,正确的是( )
A:大量饮水→垂体释放的抗利尿激素增加→尿量增加→渗透压稳定
B:炎热环境→大脑皮层体温调节中枢兴奋→散热增加→体温稳定
C:饥饿→胰高血糖素分泌增加→肌糖原分解→血糖稳定
D:剧烈运动→乳酸增加→体液中的某些离子缓冲→pH相对稳定
阅读下列短文,从每题所给的四个选项(A、B、C和D)中选出最佳选项。
There are many beautiful cities in the world, hundreds of people visit them every year. Now let's enjoy four of them.
Harbin
It's in the northeast of China. It has a long and snowy winter. Usually the winter here starts as early as October and lasts until April. Every year people come here for the Ice Lantern Festival and the winter sports.
Sydney
Sydney is in the east of Australia. It's a lively city. The weather is warm. The temperature is about 12 degrees in winter and about 35 degrees in summer. It has beautiful beaches and many parks.
Vatican City
It's the smallest city state in the world, with only 500 people in 2010. It's in the middle of Rome. It has the most visitors from all over the world, and the country gets a lot of money from the travelers.
Stockholm
There are forests, lakes and sea around it. So it has the feeling of a small town. To the east, many boats pass by every day. To the west, visitors can do many kinds of water sports like swimming and fishing.
法国大革命开始的标志是( )