【推荐1】As an important factor for us ________（consider）, physical activities must be carried out ________（assure）ourselves of health. （所给词的适当形式填空）

【推荐1】He says many Britons haven’t yet decided whom ________(elect).（所给词的适当形式填空）

【推荐2】A number of techniques have been adopted ________(approach) this problem. (所给词的适当形式填空)

【推荐3】The key finding of the study was that when crowds were further divided into smaller groups that were allowed ______ (have) a discussion, the averages from these groups were more accurate than those from an equal number of independent individuals. (所给词的适当形式填空)