控制人遗传性状的基因,位于细胞的哪一种结构上( )
A:染色体上
B:叶绿体上
C:细胞壁上
D:细胞膜上
—Excuse me, is this _______ bicycle?
—No, it isn’t. _______ is over there under the tree.
The conference will begin in an hour; ________, let's have a rest.
如图,在五边形ABCDE中,AB=AC=AD=AE,且AB∥ED,∠EAB=120°,则∠DCB=( )