Which two of the following are main ideas of the article?
1. carbon shifts from one area to others through the slow and fast carbon cycles.
2. when the ocean takes in more carbon than it releases, it becomes more acidic.
3. rain breaks down rocks, which are eventually brought to the ocean.
4. human behavior has led to increased carbon levels in the atmosphere.
question 3 options:

1 and 2

1 and 4

2 and 3

3 and 4

mendel's first law states that during the formation of reproductive cells , pairs of hereditary factors for a specific trait separate so that offspring receive one factor from each parent.

explanation:

b tumor cells have a cell wall instead of a membrane

explanation:

tumor cells different from normal cells because tumor cells have a cell wall instead of a membrane.

here is the answer

water, ice, acids, salts, plants, animals, and changes in temperature are all agents of weathering. weathering is the breaking down or dissolving of rocks and minerals on earths surface. once a rock has been broken down, a process called erosion transports the bits of rock and minerals away.