21. The children lost in the woods; otherwise, they would have been at the lakeside camp as scheduled.
It is so noisy in the restaurant and hard for us to ________ a conversation.
Studies show that people are more_____ to suffer from back problems if they always sit before computer screens for long hours.
A survey of health researchers ______ that four hours of exercise every week ____ good for our health.
----- I think Jason is wise to accept the job offer in Paris. ------__________. His career will soon get off to a good start.
________ time at Beijing Normal University, I am very impressed with the quality of the teachers and students.