Why hasn't nasa sent a spacecraft to every planet

What advantages does a pedigree have over a written passage?

Once an egg cell is fertilized by sperm, the cell then, as the embryo develops, it receives nourishment and eliminates wastes by transferring substances from its blood to its mother's blood. a. becomes a fetus immediately and exits the womb b. begins to divide and implants itself in the wall of the uterus c. remains in the uterus without dividing for several months d. travels back to the ovaries until the fetus is developed

Autonomous underwater explorers will be used to gather large-scale ocean information select the best answer from the choices provided ot