单项选择题
To relax himself before sleep, the writer often（）
A．makes a bed B．gets into his bag C．listens to music D．wears a sleep mask
单项选择题 Why can all the astronauts sleep at the same time（）
单项选择题 When the astronauts are working, sleeping bags are fastened（）
单项选择题 The proposal______, we'll have to make another decision about when to start the project.
