Scientists say it will be five or six years ________ it is possible to test this medicine on humans.
Reaching this agreement so quickly was a great____ for the meeting.
Though having lived abroad for years, many Chinese still _____ the traditional customs.
When such an organised group became too large for its members to travel together comfortably, it would ______.
By the time Jack returned home from England, his son _____from college.
Those successful deaf dancers think that dancing is an activity _____ sight matters more than hearing.