She had to work deep into the night, ______she couldn't have spread the messages to all the relevant people successfully.

If you had joined the chat room ten minutes ago, you _____________what we were talking about.  

"The interest ____ be divided into five parts, according to the agreement made by both sides," declared the judge.  

We could have arrived earlier, but Tom insisted that I _________ too fast.

---The research on the new flu virus vaccine is challenging and demanding. Who do you think can do the job?  ---____ my students have a try?