I would rather          history than geography because I can learn a lot from many historical figures.

A．study

B．studies

C．studied

D．had studied

根维管形成层首先起始于（）。

A.初生韧皮部内方的薄壁细胞

B.初生木质部辐射角处的中柱鞘细胞

C.初生韧皮部外方的薄壁细胞

D.初生木质部细胞