41.
Why do birds not have respiratory trouble at the time of flying at high altitude ?

42.
When a barometer reading suddenly recedes, it indicates that climate–

43.
When a barometer is rising air pressure is

44.
The pressure exerted by a 760 mm column of mercury at 0°C is known as

45.
If a barometric reading is falling, this usually indicates what

46.
Reading of a barometer going down is an indication of

47.
Increased wind speed is accompanied by a reduced air ________

48.
A vacuum cleaner works on the principle of pressure difference. On the moon it will

49.
Middle latitude cyclones are fueled by?

50.
Skating on ice is possible because