Answer:
The answer is below
Explanation:
The half life of a substance is the time required by that substance to reduce to half of its initial value. The half life is calculated using the formula:

Given that t = 87 years, half life = 29 years, therefore the quantity of strontium-90 left is:

That is one-eight of Strontium 90 would be left after 87 years
If it leaks at the fitting, either try to tighten the fitting, or cut it off and put on a new one.
hope this helps (:
Answer:
Higher biodiversity seems to be associated with a better response to disturbance events
Explanation:
Biodiversity means 'the variety of life'. Disturbance processes modify the environment and also affect demographic processes such as growth, recruitment, survivorship, etc., thereby producing changes in biodiversity. In an ecosystem, biodiversity contributes to its sustainability. In this regard, it has been shown that disturbance events are less important in species-rich ecosystems such as tropical wet forests compared to less rich ones (such as dry forests). The communities with higher biodiversity levels are known to be more productive in terms of biomass, and thus they seem to be more stable (and successful) to disturbance events.
In the broadest sense of the term, we have modified the genes of almost everything. We used selective breeding to breed the most resistant form of crops, the largest sized chickens, and others. In recent years we have even modified them through gene splicing and other methods. Nearly everything we eat, including including "organic" foods have been changed from their original DNA structure, in fact we do not even know anything's original genetic structure because of this. Genetic modification could also include mutations. Some crops have mutated due to pollution, disease, or other effects such as climate change. Without genetic modification our world would differ from what it looks like today.