You were silly not ________ your car．
A.to lockB.to have lockedC.lockingD.having locked在线课程B
解析：
句子使用“主语+be+adj．+to do”，所以排除C, D两项，were说明动作发生在过去，且lock的动作发生在were之前，所以用不定式完成式。