So much progress ________ made in studies that he is sure to pass the coming examination.
| A．is he | B．has he | C．he is | D．he has |
It was 80 years before Christopher Columbus crossed the Atlantic______ Zheng sailed to East Africa
| A．when |
| B．that |
| C．after |
| D．since |
It was not until near the end of the letter ______ she mentioned her own plan.
| A．where |
| B．that |
| C．why |
| D．when |
It was only after he had read the papersMr. Gross realized the task before him was extremely difficult to complete.
| A．when |
| B．that |
| C．which |
| D．What |
An awful accident, however, _____occur the other day.
| A．does |
| B．did |
| C．has to |
| D．had to |
It was probably at that moment _____ I understood what kindness really was.
| A．that |
| B．when |
| C．which |
| D．what |