Have you finished your homework– _________ . Just half of it. How about you

Look at the famous painting __________ Picasso. It’s excellent.

It ___ be the postman at the door. It’s only six o’clock.

Wang Lin failed to be admitted by Hong Kong University last year，and only then________the importance of English.

Changing the design of a new product may ______ therisk of its production in the market.