251. The America’s selling weapons to Taiwan cast a shadow on the Sino-U.S relationship. Which of the following can explain the underlined part?

A．was a good omen on

B．had ill effect on

C．was at war with

D．Effected

秦代陶塑十分发达，充分反映了秦代陶塑工艺卓越技艺的是（）。