He is only too ready to help others, seldom, _____ , refusing them when they turn to him.
| A．if not | B．if never | C．if any | D．if ever |
This ticket _____ one adult and one child to the show.
| A．promises | B．enters | C．admits | D．includes |
My son has gone abroad. I’m looking forward to him_______.
| A．return | B．to return | C．returning | D．returned |
It is good manners to eat up _______is left in your plate.
| A．that | B．what | C．which | D．all |
Can you explain ________ the sun goes down in the west?
| A．why is it that | B．why it is that | C．how it is that | D．how is it that |
A huge amount of oil was spilt on the East Sea, the causes of ______ are still under investigation.
| A．it | B．that | C．which | D．whom |