There are different types of observers. Casual observers differ from scientific observer. Seeing and observing are two different things. Not that everybody seeing is actually observing the thing.
A casual observer just sits back and watch for something to happen while a scientific observer comes up with some hypothesis to work on it.
Correct answer: A). Gathering evidence
The scientific explanation uses measurements and observations in order to explain something in the natural world. The Scientist uses the scientific method to collect evidence in the experiment that is related to the hypothesis.
They can gather the evidence by just observing the natural world and its phenomena or by performing an experiment in the laboratory or by running a model.
Hence, the correct answer would be option A.
It means that two or more cells connected together.
You can look at the word 'cell' and 'conjunctions' separately. 'Cell' is a tiny particle. 'Conjunctions' means 'two or more things connected', so just put the two meanings together.
Hope this helps. :)
The need for natural resource should increase.