By sending text messages or chatting online, we’ve been in touch for months, but I’ve never met my new friend _____.
Try your best to help the people when they are in trouble, _______you will feel pleased and happy.
_____ the right decision _____ the future is probably the most important thing we will ever do in our lives.
This is a very special flower and it can ________a strong sweet perfume at night.
Being examined twice a year is the rule that every driverobey in the city.
Keeping a diary is ____ good habit, by which you'll make ____ great progress in writing.