Leaf curling is caused by

For $3$ wheelers vehicles,which emission norm was implemented throughout the country since October $2010$?

In $1984$,the Bhopal gas tragedy was caused due to the leakage of

What are the three major kinds of impurities in domestic wastewater?

What does '$X$' represent in the given figure?

Assertion : Inhabitants close to very busy airports are likely to experience health hazards.
Reason : Sound level of jet aeroplanes usually exceeds $160 \, dB$.