chance

"My friend told me there was something in the box, but I didn't know what it was yet. "

"Let me tell you how it happened."

"The probability of passing the math test is high if you study regularly. "

"There is a possibility that the school will have a field trip next week. "

"The scholarship offered a valuable opportunity for students to pursue higher education. "

"The president of the student council used last year's debate as a precedent for this year's election rules. "

"The picnic was canceled because of the sudden rainstorm. "

"Tomorrow is my sister's birthday. "

"Their encounter was a matter of chance."

""I'll check the lost and found; perchance my wallet is there." "

"The frequent occurrence of noisy construction near my house has made it hard to concentrate on my studies. "

"The witch gave him a terrible curse."