阅读下面短文，根据短文内容填空。在未给提示词的空白处仅填写1个适当的单词，在给出 提示词的空白处用括号内所给词的正确形式填空。

A new study shows rapid decline in insect populations. A growing number of the Earth’s insect population now can 【小题1】 (see) only in collections on exhibitions. Nobody’s seen those for 400 years. A new review of over 70 studies of insect populations 【小题2】   (suggest) that human pressures are causing insect populations to decrease by as much as a quarter every decade. The loss of species is inevitable (不可避免的) because often we don’t know 【小题3】 those species are doing or how other species are depending on them.