句型转换。
1.Over three-fourths of the gas is nitrogen.（改为同义句）
three-fourths of the gas is nitrogen.
2. Everything will die on the earth without the atmosphere to protect us.（改为同义句）
Nothing could ________on the earth without the atmosphere to protect us.
3. The chorus（合唱队）of our school consisted of some students and teachers.（改为同义句）
The chorus of our school_______ some students and teachers.
4. The river is filling with heavily rain.（改为同义句）
The river ________of heavily rain.
5. I found that studying English well is more difficult.（改为同义句）
I found ____more difficult____ English well.
