23． How many hours of sleep is good for students' health?

A． Less than 9 hours．

B． Over 9 hours．

C． Only 9 hours．

D． 7 hours．

[单选题]23． How many dangers will animals meet in the deep sea?A．OneB．TwoC．ThreeD．Four

[单选题]H．ow many hours of housework did men do every week in the 1970s?A． About 23. B. About 26.C． About 13. D. About y.

[单选题]H．ow many hours of housework did men do every week in the 1970s?A．About 23.B．About 26.C．About 13.D．About y.

[单选题]The average number of hours of sleep that an adult needs is ______.A． approximately six hoursB． around ten hoursC． about eight hoursD． not stated here

[单选题]A．B．abies sleep about eighteen hours a day． Mrs Thatcher and Napoleon both said they only needed to do it three or four hours a night． Sleep，no one can live without it． But how much do we really need?Research(研究) by the National Sleep Foundation in W

[主观题]H．ow to set many-to-many relationship in Hibernate?

[单选题]23．A．likesB．likeC．likingD．likeing

[单选题]23．A．aloneB．busilyC．carefullyD．happily

[单选题]23．A．sentB．rememberedC．preparedD．shared

[单选题]First two hours, now three hours—this is how far in advance authorities are