Li Ning was able to set up a school for gymnasts in 1991, ______ he has continued to help young people to achieve their sporting ambitions.
| A．when | B．dring which | C．since then | D．since when |
Charles Babbage is generally considered _______the first computer.
| A．to invent | B．inventing | C．to have invented | D．having invented |
The matter had better _______ as it is.
| A．leave | B．being left | C．leaving | D．be left |
We’re looking forward ___________the photo exhibition.
| A．to visiting | B．to visit | C．to having visited | D．visiting |
My radio ___, I have to share a radio with my desk-mate.
| A．repairing | B．repaired | C．being repaired | D．is being repaired |
The children were last seen ___ by the river.
| A．to play | B．played | C．play | D．playing |