—I'd love to join your visit to a local museum today, but I'm on a very tight ________.—I've got a lot of work to do today.
____________ the Roman numerals, the Arabic numbers are rather simple to use.
___________ a reply, he decided to write again.
This is the material ________ in the laboratory tomorrow morning.
.I’ll go to bed now. I am not ________ up late.
.The old man said the accident ___________ carless driving, so a lot of money should be paid by the driver.