133　by and by，by the by，by and large和gradually

① by and by表示“没多久，一会儿之后”，相当于soon或after a while。

By and by the school year will be over. 不多久这个学年就要结束了。

He'll be back by and by. 他一会儿就会回来了。

② by the by表示“顺便说到”，相当于incidentally，by the way。

By the by，what happened to the boy？顺便问一下，那个男孩后来怎样了？

③ by and large表示“大体上，基本上”。

By and large，the plan is practicable. 这个方案大体上可行。

④ gradually表示“渐渐地”，相当于slowly或little by little。

The baby is gradually learning to walk. 那个婴儿渐渐地开始学走路。