Agricultural scientists are trying a new man-made vitamin on tomato plants to make them bigger and redder. they are putting the vitamin in the soil of a group of plants, and are also observing a group of plants that have received nothing other than regular water. this second group is the:
variable group.
experimental group.
placebo group.
control group

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.