Question

分析以下八句英语用的什么语法，老师要提问，麻烦具体点

分析以下八句英语用的什么语法，老师要提问，麻烦具体点We can be thankful that carbon dioxide is keeping us comfortably warm, but the concentration of carbon dioxide in the atmosphere is going up steadily and that is where the villainy comes in.
In 1958, carbon dioxide made up only 0.0316 percent of the atmosphere.
Each year since, the concentration has crept upward and it now stands at 0.0340 percent.
It is estimated that by 2020 the concentration will be nearly twice what it is now.
This means that in the coming decades, Earth’s average temperature will go up slightly.
As a result, the polar ice caps will begin to melt.
Something like 90 percent of the ice in the world is to be found in the huge Antarctica ice cap, and another 8 percent is in the Greenland ice cap.
If these ice caps begin to melt, the sea level will rise, with the result that I have already described.

Answer 1

同位语从句：先行词是thankful，后面是对thankful的解释。
过去时，in 1958是过去时态的标志词
现在完成时： has kept
主语从句：It is... that
宾语从句： means是动词，后面从句为宾语从句。
一般将来时： will begin。
一般将来时： to be
虚拟语气：

追问

第一句有that不应该是宾语从句吗？

Answer 2

过去完成时