—How was your trip to Yancheng last week?

—Wonderful! I only felt sorry that I ________ the nature reserve of red­crowned cranes, but the weather was awful.

A．could visit

B．could have visited

C．might visit

D．might have visited

瘀血头痛的特点为

A．头痛经久不愈，痛处固定不移，痛如锥刺

B．头痛如裹

C．头痛而胀

D．头痛且空

E．头昏胀痛