How did the crickets lose their ability to chirp?

By a mutation that altered the shape of their wings, making them incapable of producing the chirping noise. The feat was achieved over less than 20 generations, a mere evolutionary blink of an eye, and, with the crickets living just a few weeks, a very rapid process.

Explanation:

answer: tributaries flow into rivers.

wetland is a biome that develops when the water gets accumulated in a land exhibiting a huge depression. these form either seasonally or permanently. the water in the wetland comes from rivers, lakes, ocean, flood, rain or other sources. the wetlands includes mangroves, marshes and peatland.

tributaries flow into the rivers develops a wetland because such water will get deposited in the depression and will restrict the original flow of tributary water. hence, water with low drainage current combines with the river water.