Howlong________they________(dig)theditch?
Heaskedmewhethermybrother________(fly)toBeijing.
Iwonderifhecouldgetit________(do)beforetomorrow.
Wooddoesnotconductelectricity;________.
Somemoleculesarelargeenough________(see)undertheelectronicmicroscope.
He________methathedecidedtoleaveonMonday.
