单项选择题
A．study abroad B．work abroad C．pay for the debts D．learn to paint pictures
A．measures must be taken B．people shouldn't draw benefit from trees C．government must realize the serious results D．unless trees never be cut down
A．where there are no trees, the soil becomes hard and poor B．where there are many trees, there are fewer floods C．where there are no trees, the land might become desert slowly D．floods will make the land become desert