00-05的几个语法题求助

21、The first city in the US that [put into](A) effect major [plan](B) for [the clustering](C) of government [buildings](D) was Washington.

单数可数名词不能单独存在。改plans

24、Dolphiins are sleek an powerful swimmers that found in all seas and unlike porpoises,have well-defined beaklike snouts and conical teeth.

and前后应该是平行结构，要么都是非谓语，要么都是谓语，这里只能是谓语，B改are found.

37、By identifying similar words or structures in different languages, we find evidence that those languages are related and may be derived from same ancestor.

same前需要定冠词，改from the same.

!!Somebody help to give the answer and why. thks in advance.