The drill in Antarctica dragged on slowly because of lack of money, equipment breakdowns, environmental_________ and severe cold.
They stopped fighting but stood there, ____each other without saying anything.
The boy fell asleep where he ______,without undressing.
Some countries are increasing their use of natural gas, and other forms of ______.
Liping has never gone to Japan, but he speaks Japanese____ he were Japanese.
They have decided to ____ the household expenses to devote money to the disaster area.