Wemust______thattheexperimentiscontrolledasrigidlyaspossible.
Othersarguethatsincetheearthhasenduredalongstringoficeagesinthelasttwomilliontothreemillionyears,anywarmingis________tobetemporary.
If you want to find a decent location for your own home, ________ Mr. Smith for advice.
The boy ran out of the classroom without the teacher's _______.
In some schools children who prefer to read books rather than ________ football become social outcasts (被抛弃者 ).