1. 单句改错。I suggest A(that) the girl B(loses) some C(weight). It's good D(for) her health.
2. (改写句子,句意不变,每空只填一个词) Droughts and floods often happen there because the farmers have cut down all thetrees on the mountains. The trees on the mountains () and as a result,droughts and floods () often ()there.