Development of the embryo begins at stage 1 when sperm fertilizes an oocyte and together they form a zygote. Human development begins after the union of male and female gametes or germ cells during a process known as fertilization (Conception).
The answer is B and that is the same reason that everything stays on the Earth because it has very strong gravity.
The answer is A Plants use carbon and release oxygen, and animals release carbon and uses oxygen
Substitution i believe. There’s nothing deleted
