155. In Beijing volunteers are making use of every minute to ______ their foreign languages because volunteers must pass a written test and an interview.
The old woman is sitting_____________ her daughter.
--__________? --It depends on what it is.
__________ full preparations, we decided to put off the meeting till next week.
In such dry weather, the flowers will have to be watered if they ____________
It is the protection for the trees___________ really matters, rather than how many trees are planted.