下列各组中划线词语的用法不同的一项是（ ）

While building a tunnel through the mountain, ________ .

Jimmy is very tall. He is taller than in his class.

Scientists say they have found a way to produce the human body’s own cancer-killing cells through gene treatment, ______ new hope to cancer sufferers

With few people ________ pigs, the price of pork _______