Answer:
According to the following position vs. Time graph the bicyclist was : D
D. Not moving for the first two seconds, then begin moving at the constant speed.
Explanation:

Along Y-axis = Distance in meters
Along X-axis = Time taken in second
- For first 2 seconds the The object has not changed its position.There is Zero distance covered.So , Speed = 0
- After 2 second,The Object changed the distance by equal amount in equal interval of time.(Uniform Speed).Hence at each point after 2 second, there is same value speed
First read the introduction.
Seconds look at the pictures how to build it.
NaHCO₃ + HCl → NaCl + H₂O + CO₂
<u>Explanation:</u>
NaHCO₃ + HCl → NaCl + H₂O + CO₂
When Sodium bi carbonate (NaHCO₃) reacts with hydrochloric acid (HCl), it forms table salt (NaCl), water ( H₂O ) and Carbon di oxide (CO₂) gas is evolved.
Here base reacts with acid to form salt and it is the neutralization reaction.