Answer:
double fertilization
Explanation:
Flowering plants or angiosperms are seed-producing plants with the ability to produce reproductive organs-flowers and fruits with seed in it (unlike gimnosperms which contain naked seed). Another distinctive feature of angiosperms is their reduced gametophytes. This feature most likely reduces the time between pollination and fertilization. Fertilization in flowerin plants is double, meaning that two sperm cells fertilize ovule cells(egg cell and central nuclei cell): one forms diploid zygote which will develop in embryo, while other form triploid cell which will develop into endosperm (provides nutrition for the embryo).
The first thing that the farmer should do is formulate a hypothesis in which he will make intelligent guesses on what is happening or develop a theory of which would explain what is happening. It is the first step in scientific investigation in order to formulate questions of why weeds that are sprayed does not die. After this, it is only then the farmer should experiment and after that, he should finalize his findings as it is its conclusion to the problem.
a chemical landfill is where chemical waste is stored once it has been used
if it is secure it means that the waste cannot pollute the environment through water, air etc
Convective zone is the answer. If you need an explanation just ask.
Hope this helps :)