The correct answers are D. Clouds and B. Storm systems.
Step-by-step explanation
Convection currents are the result of a physical-chemical process in which chemicals are heated and this decreases their density, causing their elevation. At the same time, the elements in the top sink because of lost temperature and increase in density, creating a cycle. According to the above, the correct answers are B Clouds and D. Storm Systems. Clouds are the result of a cycle of water, in which the water on the earth in a liquid state evaporates due to the caloric energy from the sun, changing to a gas state and go up until becoming droplets again in a process called condensation forming cloud. Once the cloud is very heavy and lost its temperature, it precipitates to the earth due to the force of gravity, and then the cycle starts again. Secondly, storm systems are a kind of cloud, those clouds develop vertically thanks to the convection process, in this, the same process occurs but the clouds have an internal air stream that makes that the clouds grow up vertically producing storms, those clouds are known as Cumulonimbus and Cumulus congestus. So, the correct answers are D. Clouds and B.Storm systems.