It remains doubtful whether the project _____________ next month will bring profits to the company.

When first __________ to the market, the computer software was not a success due to its complexity in operation.

Unfortunately, the element Madam Curie devoted all her life              her death.

______ a happy life, try to look at the positive side in every situation.

There are several factors _______ in the economy _______ make it difficult to predict the future.

---- Have you ever seen a dictionary ____________ our school library?
---- Yes, it is over there and Mary is using it.

Earth is believed ______ by an object the size of Mars at some point in the distant past  
before its surface cooled．

With temperature ______ so rapidly, we could not go with the experiment．

       nice, the fruit has a good sale.

I mean       the meeting tomorrow, but what he has just said means    the meeting.