Please let us________ if you have good suggestions, however, we ________ the difficulty working out the subject early．A.know; recognizedB.recognize; knowC.recognize; recognizedD.know; recognize
网友回答
A解析考查两个动词know和recognize的用法．从整个句子来理解，第一空Please let us know意思是请告诉我们，从而可排除B和C两项，再从时态来分析，应选A．