It is good manners to eat up _______is left in your plate.
| A．that | B．what | C．which | D．all |
________ there are living creatures in the outer space as those on Earth hasn't been proved until now.
| A．How | B．When |
| C．Where | D．Whether |
We haven't settled the problem of ________ it is necessary for him to study abroad.
| A．why | B．whether |
| C．what | D．how |
It surprised us all ________ Kate made such big progress in this final exam.
| A．when | B．that |
| C．how | D．whether |
________ some teenagers don't realize is ________ difficult life can be after they get addicted to drugs.
| A．What; what a | B．That; how |
| C．What; how | D．That; what |
_______ didn't attend the lecture yesterday won't be given full marks.
| A．Any one | B．Whoever |
| C．Who | D．The person |