Look, the lights in the room don’t . Someone must forget .
| A．put out; going them out | B．be out; put them out |
| C．go out; to put them out | D．go out; putting them out |
--How often do you drop your English teacher a line?
---________. But usually once a week.
| A．As usual | B．It depends | C．Generally speaking | D．Have no idea |
Some English scientists are identifying problems ____ technology in the 21st century. If solved, the solutions could change the world.
| A．facing | B．faced | C．being faced | D．having faced |
Exactly ____they did when at last they reached the sea remains a complete mystery.
| A．that | B．how | C．which | D．what |
One thing’s for sure, the fire _____by some cigarette butts.
| A．might cause | B．could have caused |
| C．must have been caused | D．should be caused |
You could ________ this a really nice room if you bought a new carpet.
| A．make | B．turn | C．grow | D．get |