---Is everyone here? ---Not yet. Look, there_______ the rest of our students!
John's success has nothing to do with good luck. It is years of hard work _______has made him a great scientist today.
It was 80 years before Christopher Columbus crossed the Atlantic______ Zheng sailed to East Africa
It was not until near the end of the letter ______ she mentioned her own plan.
It was only after he had read the papersMr. Gross realized the task before him was extremely difficult to complete.
An awful accident, however, _____occur the other day.