柳树叶片正面绿色深，背面绿色浅的原因是　 [ ]

A．正面上表皮比背面下表皮薄 　

B．上表皮比下表皮的叶绿体多

C．栅栏层比海绵层的叶绿体多 　

D．海绵层比栅栏层的叶绿体多

—Could you tell me _______, Mary?

—Of course. Go straight, and you’ll see it on your right.

A．where is the cinema

B．where the cinema is

C．where was the cinema

D．where the cinema was