To determine which two points on the number line are opposites, we first need to locate each point based on the descriptions given:
- Point A: 1 mark to the left of negative 1 is -2.
- Point B: Half-way between negative 1 and 0 is -0.5.
- Point C: Half-way between 0 and 1 is 0.5.
- Point D: Half-way between 1 and 2 is 1.5.
Now, let's identify the opposite of each point:
- The opposite of A (-2) is 2.
- The opposite of B (-0.5) is 0.5, which is Point C.
- The opposite of C (0.5) is -0.5, which is Point B.
- The opposite of D (1.5) is -1.5, which is not represented in the points given.
We can see that the opposite pairs are:
- Points B (-0.5) and C (0.5).
Therefore, the two points on the number line that are opposites are points B and C.