—What happened to you on your way back to the hotel last night ?—I lost my way in complete darkness and, ________ things worse , it began to pour .

Our international conference is about the children ______ to domestic violence.

  __  carefully if any change occurs when doing experiments in the lab..

Many applicants stood outside the manager’s office, nervously waiting _________ for the job. 

Be careful when you deal with this chemical, as it will explode when ______ to sunlight.