insensitive. She's completely insensitive to my feelings.

back out. you promised to help me this weekend- you can’t back out now.

inquisitive

In the light of recent incidents, we are asking our customers to take particular care of their personal belongings.

Once in a blue moon My sister lives in Alaska, so I only see her once in a blue moon.

Lock horns = debate, argue, have row with locking horns (noun) = debate, argument The mayor and her deputy locked horns over plans for the new road

Earthquakes result in a great loss of life.

take over. When Mr Baker retired, his daughter took over the family business.

We must reach Khartoum at any cost.

The landlord was very generous to us. All that we consumed in his inn was on the house.

in the nick of time

up in the air