Jack had sent some e-mails, he _______ workingon his project.

Hi, Jack!—Hi, Eric! You ________ really quiet, but now you arevery outgoing.

There is no doubt _______ nearsightedness is a serious problem among the youth of our country.

_______ oranges do you want and ______milkwould you like

Global warming is a big _______ for all and it’simportant to raise awareness about climate change