Some plants are so difficult to grow that they can only ______ in a perfectly clean environment.

idn’t you buy the gold ring —- I ______,but I didn’t have the money.

elieved ______40% of stars, like the sun, mayhave planets that orbit them

There’s ______ ball on the ground.Would you please pass ______ ball to me?—With pleasure.

It sounds to me as if he knows a lot about computers.—He is a person who is fond of________.