【正确答案】

【答案解析】(should) keep[解析] 虚拟语气用在主语从句中，谓语要用should+动词原形(或省略 should)用动词原形；注意点：虚拟语气；类似结构：It is (was) important (necessary，desirable，advisa ble) that．．．或it is (was) desired (suggested，settled，proposed，requested，decided) that．．．