bit by bit

形容词 bit by bit:

1. one thing at a time
   同义词：bit-by-bit, in small stages, piecemeal, step-by-step, stepwise

副词 bit by bit:

1. a little bit at a time
   同义词：piecemeal, little by little, in stages
2. in a gradual manner
   同义词：gradually, step by step

1. He saved money bit by bit until he have enough to buy a car.
   他一点儿一点儿攒钱直到够买一辆汽车。
2. He saved money bit by bit until he had enough to buy a car.
   他一点儿一点儿攒钱直到够买一辆汽车。
3. He assembled the model aircraft bit by bit.
   他一块一块地装配飞机模型。
4. She committed six new$100 bills to the hands of her parents and asked them to let her have the money back, bit by bit, as she needed it.
   她将6张面额为100美元的新钞交给父母保管，嘱咐他们在她需要钱时，分期分批地交还与她。