20．　　　　 is known to us all is that the old scientist, for　　 life was hard in the past, still works hard in his eighties.

A．It; whose　　　　 B．As; whom　　　 C．As; whose　　　 D．What; whom

19．We wanted to get home before dark, but it didn’t quite　　　 　　as planned.

A．turn up　　　　　 B．turn out　　　 C．carry on　　　 D．carry out

18．The driver’s injuries were of little worth compared with　　　 suffered by his passengers.

A．ones　　　　　　 B．those　　　　　 C．his　　　　　　 D．theirs

17．It is the usual　　　 in our school that if you spoil any material, you’ll have to pay for it.

A．order　　　　　　 B．deed　　　　　 C．opinion　　　　 D．practice

16．The users of this new mobile phone can check e-mails　　　 they happen to be.

A．whatever　　　　 B．wherever　　　 C．what　　　　　 D．where