That suggests that catch-up sleep may undo some but not all of the damage that sleep deprivation causes, which is encouraging given how many adults don’t get the hours they need each night. Still , Liu isn’t ready to endorse the habit of sleeping less and making up for it later.
A.
express formal support or approval for someone or something
B.
sign your name on the back of a cheque to show that it is correct
C.
say in an advertisement that you use and like a particular product so that other people will want to buy it
D.
to write details of a driving offence on somebody's driving license