((*Will mark brainiest to the first right answer for my question AND my riddle ;>*)) Which of the following statements is true?

Before Jenner's vaccine, there was no prevention for smallpox.
Edward Jenner developed the first vaccine for cowpox.
Vaccination is only necessary for children under 5 years old.
Missed vaccinations can be given during "catch-up" periods.

*Riddle Time!*

A girl, at the funeral of her mother, met a guy whom she did not know. The girl fell for the guy and wanted to contact him. She looks for him but couldn’t find him. A few days later she kills her sister. Why did she do that?

This is really late but uh

The answer is A. (Looked it up)

The answer to the riddle is probably that the guy was the sister's husband :P

d concave shape of wave rock

explanation:

the concave shape of wave rock is a very good evidence that supports the evolution of earth due to chemical weathering. if we talk about structure of   wave rock, studies have estimated that it is around 2.7 billion years old. it also serves as the foundation of evidence that it was the place where australian continent began to form.

how the structure of wave rock was created?

studies suggest that structure of wave rock was created when the surrounded area was started to weather due to which deposition of material started on the part of land which now contains wave rock.

the structure of wave rock is considered to be one of the best-known landforms in australia. at the height of around 15 cm, there can be found flared slopes which formulate the margins of hyden rock. it is now assumed by geologists that wave rock was created by subsurface water-induced weathering and not by glaciers, waves or wind.

due to deposition of material over the period of long time, the wave rock became tougher and tougher due to weathering from surrounding terrain. this makes it a physical evidence that supports   the evolution of earth due to chemical weathering.

hope it !

a- all cells come from pre-existing cells