It is his cleverness, not his strenth, ____ defeated his rival.

 It is important to introduce children to healthy nutritious foods from ________ they begin to eat solids.

It just isn’t fair. _____ I was working as a waiter last month, my friends were lying on the beach.

More than 100 students have entered for the competition and　　　gains the most points will be the winner. 

—When did your cousin begin to show his interest in medicine?—It was a Saturday ___ she noticed her uncle experimenting on a frog in his lab.