In general, the rate of a reaction can be increased by
1. all of these
2. increasing the concentration of reactants.
3. increasing the temperature.
4. adding an appropriate catalyst.

1. All of these

Explanation:

The rate of a reaction depends on following factors:

1. increasing the concentration of reactants: means there is more particles of reactants per unit volume.Thus more particles can collide and hence the rate of reaction increases.

2. increasing the temperature- the particles move faster and undergo more collision which leads to an increase in the rate of the reaction.

3.adding an appropriate catalyst: addition of catalyst lowers the activation energy and thus more reactants can cross the energy barrier. Thus it leads to formation of more products hence an increase in the reaction rate.

Thus the rate of a reaction can be increased by  all of these.

explanation:

venn diagram is pictorial representation with of circles showing the relation between two finite sets or things. the intersection part of two circles conveys the relation present in between those sets or things.

here in the venn diagram of sand and salt two circles represent sand and salt. but the area falling under the intersection of these circle represents the mixture of sand and salt.

so, in a venn diagram the mixture will be placed in a middle that is in between the intersection of two circles.