I didn’t quite follow him because he explained the theory _____that is too abstract for me.
If only I _______ more confidence in the English speech contest held last week!
According to the school rules, no child _______ be allowed out of the school during the day, unless accompanied by an adult.
It was not until 1911, _______ the first vitamin was identified, _______ people realized the importance of it.
The moment I completed the 800-meter race in the school sports meet, my legs _______.
We’ve just heard a warning on the radio _______ a typhoon may be on its way.