Don't use water to put out the fire if oil catches fire. As is known, oil ________ float on water.
John plays basketball well, _______his favorite sport is badminton.
The day________ he was looking forward________ in the end.
—Who ________ it be that is knocking at the door? —It________ be Mother, but I’m not sure.
If you cheat in the exam, you could hardly________ it.
He once studied in Zhejiang University, ________he went abroad for further study.