With reference to `Astrosat', the astronomical observatory launched by India, which of the following statements is/are correct?

1. Other than USA and Russia, India is the only country to have launched a similar observatory into space.
2. Astrosat is a 2000 kg satellite placed in an orbit at 1650 km above the surface of the Earth.

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In the cities of our country, which among the following atmospheric gases are normally considered in calculating the value of Air Quality Index?

1. Carbon dioxide
2. Carbon monoxide
3. Nitrogen dioxide
4. Sulfur dioxide
5. Methane

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Recently, linking of which of the following rivers was undertaken?

Regarding DigiLocker', sometimes seen in the news, which of the following statements is/are correct?

1 It is a digital locker system offered by the Government under Digital India Programme.
2. It allows you to access your e-documents irrespective of your physical location.

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Which of the following is/are the advantage /advantages of practising drip irrigation?

1. Reduction in weed
2. Reduction in soil salinity
3. Reduction in soil erosion

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'European Stability Mechanism', sometimes seen in the news, is an