Answer:
Alexander Fleming
Explanation:
Which scientist developed the idea that microorganisms can cause diseases?
Paul Ehrlich
Answer:
Explanation:
The most primitive tool I used today was the hammer. The hammer is age long in the history of household tools. It is used to hit in nails into walls or woods.
The most advanced tool I have used today is the mobile phone. This is a tool of the 21st century which makes communication easier and faster.
The correct answer is B. Ordovician period
Explanation:
Plants are mainly multicellular organism that depends mainly on photosynthesis to obtain energy, this includes a wide variety of species such as grass, flowering plants, trees, shrubs, etc. Additionally, plants are considered as one f the two major divisions or kingdoms along with animals. In terms of history, it has been determined first land plants appear during the mid-Ordovician period around 470 million ago, although organisms that were the origin of land plants developed in water in previous periods, also by the Devonian period a wide variety of plants have emerged with features that are still part of plants nowadays. Therefore, plant life first appeared on land during the Ordovician period.
