环保专家利用地理信息系统来追踪森林覆盖率的变化。

Environmental experts use ___GIS to track changes in forest cover.

均衡的饮食有助于保持你的消化系统健康。

A balanced diet helps keep your ___GIT healthy.

许多美国大兵在服役期间会收到家人的信件和包裹。

Many ___GIs receive letters and care packages from their families while serving.