确定城市输配系统的压力级制、管径、燃气管网、构筑物及防护和管理措施,都与所使用燃气的()有关。
A、温度
B、种类
C、含湿量
参考答案:B
读“南极洲等高线圈”(图甲)和“南极洲4个气象站气温曲线图”(图乙)回答1—3题。
1、法拉第站在哈利湾站的 [ ]
A、西北方向
B、东北方向
C、东南方向
D、西南方向
2、关于四个气象站气温的正确叙述是 [ ]
A、最低气温均出现在7月
B、各站之间的气温差异夏季最大
C、气温季节变化最小的是法拉第站
D、南极气温年较差为22℃
3、东方站各月气温都比南极低,主要原因是东方站 [ ]
A、纬度比南极高
B、海拔比南极高
C、受副极地低压控制
D、终年盛行西北风
Imagine fishermen walking down to the seashore, ready to carry out their early morning routine of preparing their boats and net. (51) they hope for a good catch of fish. But to their (52) , a horrible sight meets their still sleepy eyes. Thousands of fish have been washed ashore dead. The cause of this mass destruction—A red tide!
Red tides are a global (53) . They have been observed on both the Atlantic and the Pacific coasts of the United States and Canada. They have also occurred in many other places. Though relatively few people are (54) them, red tides are not new.
In the Philippines, a red tide was first seen in the province of Bataan in 1908. Since then, red tides have been seen in many other (55) . A Philippines red tide expert told us that " (56) the fish kills, the Philippines has documented 1, 926 eases of dead shellfish poisoning caused by red tides. "
The term "red tide" (57) the discoloration of water that sometimes occurs in certain areas of the ocean or sea. Although the color is often red, it may also be (58) of brown or yellow. The World Book Encyclopedia reports that "the discolored areas may range from (59) a few square yards to more than 2,600 square kilometers. "
What causes such discoloration Red tides are generally caused by several species of single-celled organisms. These tiny organisms have hair-like projections which they use to (60) themselves in water.
55().
A. sandy beaches
B. river mouths
C. coastal areas
D. reef areas