Luggage may not be brought into the building ________ a guard has checked it first.

It was reported that two roads being closed in Teesdale ________icy road conditions. [ ]

The lecture given by Professor Johnson on the Antarctic is very attractive, and at the beginning, it is _____ asking us questions about the mysterious continent.[ ]

Shelly had prepared carefully for herEnglish examination so that she could be sure of passing it on her first________

Sorry, I would have come earlier, but I ______ that you were waiting.