Our school is no longer ____ it was 10 years ago, _____ it was not well equipped.

A．what, which

B．that , which

C．what, when

D．that, where

植物的顶芽优先生长而侧芽生长受到抑制的现象，称为“顶端优势”。下列现象中，与顶端优势现象中生长素作用的二重性相同的是（）

A.茎的向光性

B.根的向地性

C.茎的背地性

D.A、B、C都相同