— How much of the foreign expert's speech have you understood?

— Next to nothing. I wish I _____ harder at English.[ ]

A. worked

B. had worked

C. would work

D. were working

进化水平最高的孢子植物是（）

A.被子植物

B.裸子植物

C.苔藓植物

D.蕨类植物