The final examination is coming up soon. It’s time for us to ________ our studies.[ ]

When did your uncle arrive ____ China—He got to Guangzhou _____ the morning of the 16th of April.

Some people who don’t like to talk much are not necessarily shy; they _____ just be quiet people.

News that the president’s life was________could cause the nation’s economic crisis to become worse.[ ]

Since David ______ downloaded a virus into his computer, he can not open the file now