天气好的话 学生们就去徒步旅行 _________________________if it is a fine day.
由于交通状况不好 西蒙迟到了
Simon was late_______________________.
老虎的数量变得越来越少了 因为他们的栖息地变成了农田
The number of tigers is______ and ______ because their _____ are becoming_____.
野生动物的生存林地的丧失是个很严重的问题
The ________________ of wild animals is a very serious problem.
如果我们再不保护野生动物 世界上就再也没有野生动物了
If we ___________ them any more,there _________________________wild animals in the world.
就要交了