Direction: Read the given passage and choose the correct answers for the questions given below.

The pockets of methane trapped within Canada’s frozen Lake Abraham are a natural wonder, ____1____ yet with a deadly core. These beautiful, ethereal blue orbs indeed have a dark side. Although produced by a natural process, the alluring ice-encased bubbles enclose a ____2____ greenhouse gas and therefore a threat to the planet.

The story of how the bubbles come into being is far from appealing and, as with many a horror story, it ____3____ with dead bodies. Microbes feeding on the decomposing organic matter at the bottom of the lake release methane, which floats to the surface in bubbles. When the water freezes in winter, these bubbles become trapped, producing magical landscapes. But come the spring thaw, the bubbles pop, releasing the methane within them to the atmosphere. Methane is highly inflammable and so the bubbles explode when set ____4____. Its real danger lies in its impact on Earth’s temperature. Although methane doesn’t stick around in the atmosphere like carbon dioxide, its heat-trapping effect is 34 times stronger, making it potentially far more ____5____ to our climate.

This pretty-but-pressing problem isn’t limited to Canada. Russia and US scientists have also measured methane emissions from thawing bogs in Siberia, and as the climate warms, more once-frozen lakes could also start releasing their gases.