Mr. Smith is very happy because the cars made in his factory have never been ______.

She worked deep into the night _____ a long speech for the president. [ ]

The two things _______they felt very proud were Jim’s gold watch and Della’s hair.

下列各句，没有语病、句意明确的一句是（ ）

Obama delivered a speech to 500local youths during his visit to China, many of ____ from Fudan University and Tongji University