Please help me to get started!!
1a) Belgians had mistreated someone from Dhaka (11)
6d) First off, thermoter is in a faulty element in tank (9,6)
7d) Tyne's diverted round motorway, creating opposition (6)
18a) Man in pub completely reversed this treatment (5)
Is 1d) Beneath the sheets (Clue: Hidden meaning where sleepers lie)