It puzzles the scientists _____ some mammals produce their young _____ others lay eggs.
| A．that; while | B．what; while | C．that; as | D．what; as |
__________ some medals came to live in the sea is not known.
| A．Which | B．Since | C．Although | D．How |
____ method you choose, so long as you finish the job on time.
| A．It isn’t a matter to me what | B．What doesn’t matter is that |
| C．It doesn’t matter to me which | D．No matter which |
I am so glad that I have found the same modern computer ____ I am working on.
| A．which | B．as | C．that | D．where |
. We would do more such exercises in the future, I think, ____we did yesterday.
| A．as | B．which | C．that | D．than |
. ____ it will do us harm or good remains to be seen.
| A．If | B．Whether | C．That | D．Where |