We share a_________ purpose, so let’s help each other.
It may rain --- you’d better take an umbrella _________.
A notice was placed by the river bank warning people to ___________ the thin ice.
I was close to being killed the other day. A car passed me at ____ I thought was a dangerous speed.
After half a year’s training, they were made entirely used ____ underwater.
Thank you very much for the trouble you have taken _________ me with my English.