guard 意為 留心守望,警戒 ,防止可能的 攻擊或侵害.攻擊或侵害.
eg.Soldiers ___ the research center with guns every day.
watch意為 觀看,集中注意力觀看事物的變化與發(fā)展.
eg.We often watch monkeys jump in the zoo.
observe意為 觀察,從不同的角度長期的觀看并進行研究.
eg.Tom observed the behaviours of snakes in his life.
inspect意為 檢查,進行觀察,為了發(fā)現問題進行仔細而挑剔的檢查.
eg.The mayor inspected our school just now.