________ the convenience of digital payment, many senior citizens started to use smart phones.
To enjoy
Enjoying
To have enjoyed
Enjoy
The number of medical schools reached 18 in the early 1990s and ______ around that level ever since.( )
are remaining
have remained
is remaining
has remained
I never worried about my son while I was away because my mother ______ him.( )
drank a toast to
played a joke on
kept an eye on
made an apology to
According to Professor Johnson,we don't have to read the book if we don't want to,as it is ______.( )
worthwhile
necessary
optional
serious
Dr.Rowan,______ secretary resigned two weeks ago,has had to do all his own typing.( )
whose
of whom
of which
which
﹣Shall I order a taxi for Sarah to go to the airport tonight?
﹣______.I'll drive her there.( )
Have a try
Don't mention it
Don't bother
Go ahead