Me asap some plants close their leaves for protection when they are touched. this is an example of which tropism? hydrotropism phototropism gravitropism thigmotropism

It's Thigmotropism

The correct answer is thigmotropism.
Hydrotropism is when roots grow towards water.
Phototropism is how plants seem to "bend" towards a window where light comes in.
And gravitropism is how seedlings and saplings of plants know to grow upwards, against gravity, through and out of the soil.

The speed of  sound:   sound travels  at different speeds depending on what it istraveling through. of the three mediums (gas, liquid, and solid)  sound waves travel the slowest through  gases, faster  through  liquids, and fastest  through  solids.

Your asshahs has a nice