23.— What’s that terrible noise.David? — Oh,I forgot to tell you.The new machines in the nearby plant _______.
It i s the second time that the poor area_______.
In modern times, the development of science is ________ .
He insisted that his plan _______ carried out at once.
In order to have a good _______ of English, he decided to go abroad for further education.
A series of books in the library ____ been stolen so that the number of them ____ smaller than before.