The phrase "activity that started" is correct and usable in written English.
It can be used to refer to an action or event that began at a specific time or under certain circumstances.
Example: "The activity that started last week has gained significant interest among participants."
Alternatives: "event that commenced" or "action that began".
The Atlantic Ocean is in a cycle of frenetic hurricane activity that started a decade ago.
But the surge in economic activity that started last fall got juices flowing.
For the first time since humans began weighing objects -- an activity that started before recorded history -- mankind now had a method that did not rely on balancing the force exerted by the object being weighed against some other weight or force.
Investigators followed spending activity that started at his bank and led to a prostitution ring.
Thus, the monitoring of an eruptive activity that started in a phreatic manner needs careful attention whether the activity diminishes or becomes more vigorous toward magmatic activities.
In previous experiments, in which we used the same mode of nitroglycerin infusion, we observed an increase in spinal trigeminal activity that started immediately and reached significance 25 min after onset of the infusion [18].
The most widely studied of such event-related changes is a split-second bump in electrical activity that starts anywhere from 300 milliseconds to 800 milliseconds after a recognized stimulus.
It is defined as neuronal activity that starts once a forthcoming movement is instructed and continues until the movement is executed (Weinrich and Wise, 1982; Wise, 1985).
Try enrolling in a summer afternoon class, organization, or activity that starts after summer school.
Further, seizures appeared to be initiated with low voltage fast activities that started 1 2 s earlier in the hippocampus than in the cortex (Fig. 4A).
The July 16, 2013, game in Flushing will be preceded by activities that start the Friday before.
