Questions

southern region is closest to equator and thus receives sunlight for longer duration than any other part of India

Controlled railroad crossing includes warning signs, red lights and railway gates, whereas absence of all of these warning signs like red lights and gates includes uncontrolled railroad crossings. 

Carbon monoxide is one of the major pollutant present in the world. The six most common pollutants include ozone, carbon monoxide, sulfur dioxide, lead, nitrogen oxides, and particulate matter.

Carbon monoxide is a common atmospheric pollutant. It is produced largely in combustion processes like in industries and in vehicles. It is a gas that cannot be seen nor smelled.

One word substitute for "That which cannot be heard" is Inaudible.

Indian teen Rifath Sharook from Tamil Nadu has designed the world’s lightest & smallest satellite named “KalamSat”. The satellite weighs only 64 grams and will be launched by NASA on June 21, 2017. With this, he will become the first Indian student to have his experiment launched by NASA. The main role of the satellite will be to demonstrate the performance of 3-D printed carbon fibre. The satellite has been designed in a way which will have a 240-minute mission in space and will operate for 12 minutes in a micro-gravity environment of space.