—Would you like to go and watch a tennis match this weekend with us?—I'm sorry, but I've got ________ plans.
The fact has worried teachers and parents ________ more and more students have got near-sighted.
Thanks to the Internet, we have_________ to data quickly and effectively, regardless of where we are and what we are doing.
In order to live with happiness, we must learn to _____work with pleasure since as much as one of three life span or so will be spent on it.
Tony failed to finished his paper on time. If he ______ me about it, I would have came to his help.
There is an increasing concern _____________ about Ebola infection. Every country has taken necessary measures to prevent it.