മോണ്ട്രിയൽ ഉടമ്പടി ഒപ്പുവച്ച വർഷം ഏത് ?
A1987
B1997
C1992
D1981
A1987
B1997
C1992
D1981
Related Questions:
Consider the following statements:
The exosphere merges gradually into outer space.
This layer has the highest density in the atmosphere.
Which of the above is/are correct?