人们利用 植物的叶只有一层细胞,容易受到有毒气体侵害的特点,把它 当做检测空气污染程度的指示植物。
除非我们仔细点,否则我们不能把工作做好.
we are careful, we can't do our work .
改过不嫌晚.
It's never late mend.
This volleyball must belong to Carla.(改为否定句)
This volleyball Carla's.
At first, he didn't know what he could do in the new group.(改为简单句)
At first, he didn't know do in the new group.
How's the weather today?(改为同义句)
the weather today?