As you are lifting a box, someone places extra weight on top of it. for your muscle to continue contracting and lifting the box, the muscle must

The muscle must change its contraction, wave summation and twitch mode.

Explanation:

Muscle tissue is important for the contraction and movement of an organism. Muscles contain important protein like actin, myosin and troppomyosin that helps in the movement of a particular part of a body.

While lifting a box, if someone put extra weight the muscle will shift from isometric to isotonic contraction. The muscle decreases the wave summation and turns to fast twitch mode for the continuous contraction and lifting the box.

i think it would be b. tissue because an organ system is a group of organs that work together to perform one or more functions. each does a particular job in the body, and is made up of certain tissues.

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.