Choosing to visit the Shanghai Expo on a late afternoon can make you see two to three times as many of the most popular pavilions between 6 pm and closing time ____ you hurry.
A beam of light will not bend round corners unless______to do so with the help of a reflecting device .
Bad luck .Our maths teacher keeps us ______too much homework.
He ______to catch the last bus but she was too late .
----Doesn’t she work here ? ----________.
----Have you learned English before ? ----Yes,I _____English for 6 years in my hometown .