16.
You had better got your reservation well in advance or you won't be able to go.

17.
The discovery of the radio and the television have not been without some effects.

18.
He is in the habit of purchasing the very good of all things available.

19.
Holmes took up a second letter which lay unnoticed upon the table whilst he had been absorbed with the first.

20.
His salary is not adequate for him to make the both ends meet.