—I wonder why he has been acting so strange these days. —Recent pressure at work may ______ his behavior.
Some people waste a lot of food _______ others haven’t enough to eat.
Come and visit me whenever _______.
---Will Tony come to the party tonight? ---I’m not sure. He _______stay at home preparing for the coming exam.
The house I grew up _______ has been pulled down and replaced by a hospital.
______ the project in time, the staff have been working at weekends since last summer.