______ into use in April 2000, the hotline was meant for residents reporting water and heating supply breakdowns.
A. Put B. Putting C. Having put D. Being put
He got well-prepared for the job interview, for he couldn’t risk _______ the good opportunity.
A. to lose B. losing C. to be lost D. being lost
Professor Smith, along with his assistants, ______ on the project day and night to meet the deadline.
A. work B. working C. is working D. are working
The shopkeeper did not want to sell for ______ he thought was not enough.
A. where B. how C. what D. which
With more forests being destroyed, huge quantities of good earth ______ each year.
A. is washing away B. is being washed away
C. are washing away D. are being washed away
It was some time ______ we realized the truth.
A. when B. until C. since D. before
