D. A duck flies to another pond.
The above sentence is an example of emigration. Emigration refers to moving from one area to another for a long or permanent period. In this instance, a duck is leaving the pond it originally resided in (along a population other ducks) in order to reside in another pond. Therefore, it can be said that the duck "emigrated".
The answer is through the placenta. The placenta is formed in the uterus of the pregnant woman. Its role is in the nourishment of the fetus. The placenta provides the fetus with nutrients and removes waste. The umbilical cord connects the placenta to the fetus and it serves as the transporting passageway.
The answer is c because the earth not only is tilted it orbits