There's no way of knowing why one man makes an important discovery ________ another man, also intelligent, fails.
—What do you think of store shopping in the future? —Personally, I think it will exist along with home shopping but _____.
In the near future, more advances in the robot technology _____ by scientists.
Close the door of fear behind you, and you _____ the door of faith open before you.
Don’t worry. The hard work that you do now _____ later in life.
—Can I call you back at two o’clock this afternoon? —I’m sorry, but by then I _____ to Beijing. How about five?