人体细胞中染色体、DNA、基因的关系是( ) A.每条染色体中有一个DNA 分子,DNA上有一定数量的基因 B.染色体的数目是不一定的,每条染色体中有一个DNA分子 C.染色体的数目是一定的,每条染色体中有多个DNA分子 D.每条染色体中有一个DNA 分子,DNA 上有一个基因
Please be quiet! Your little brother in the bedroom now.( )
slept
sleeps
is sleeping
will sleep
Nowadays people wish to eat______food than before to keep fit.( )
healthy
healthier
healthiest
the healthiest
There are tourists visiting the Great Wall on May Day every year.( )
two thousands of
two thousands
thousands of
thousand of
Mrs.Green showed the boys how to do things like a gentleman at the dinner table.( )
happily
bravely
differently
politely
Must I wash the dishes right now?
No, you .( )
needn't
wouldn't
mustn't
for