一列地铁从一条645米长的隧道通过,这列地铁长75米,每秒行24米。这列地铁几秒可以通过隧道?
(645+75)÷24=30(秒)
–Would you mind _________ your voice down? We are doing our homework.
–Sorry for that.
A.keep
B.keeping
C.to keep
D.kept
先天性全色盲的遗传方式是()。
A.常染色体隐性遗传
B.常染色体显性遗传
C.性连锁显性遗传
D.性连锁隐性遗传
E.多基因遗传