Answer: Earth spins on its axis
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Answer:
Access. A basic feature of any greenhouse is access. ...
Vents. One of the first greenhouse features necessary is a means of controlling the climate – most importantly, venting excess heat. ...
Fans. Fans inside a greenhouse are necessary for two basic functions. ...
Rollup Sides. ...
Heaters. ...
Shelves and Benches. ...
Water. ...
Electricity.
Explanation:
theres more but these are the important ones .
Answer:
They contain protein fibres that can contract when energy is available, making the cells shorter.
