甲、乙两种物质的质量之比是5∶4,降低相同的温度时,放出的热量之比是25∶4,则甲、乙两种物质的比热之比是( )
Who will you ask to help with the work,Lucy or Lily?﹣Lily.She is much ________.( )
careful
more careful
most careful
Must I clean the room now?
No,you ________.You can do it later.( )
needn't
can't
may not
There's little ________ left at home.Go and buy some,dear.( )
carrots
potatoes
rice
How long can I keep this dictionary?
Two weeks.You must ________ it on time.( )
collect
call
return
The 31 stOlympic Games will take place ________ August,2016.( )
in
on
at