It is said that the gravity on Mars is only about __________ of the gravity on earth.
--Where is Jack? --He’s left a ______saying that he will be back in a minute.
Do you know _______ the number of students in our school ______?
一Oh, so many people are standing outside the hall. _______will the film start?一__________seven o’clock.
When the students arrived there out of ______, the train _______ for about five minutes.
The clothes need_______ but you_______ do that by yourself.