他在书桌前徒劳地坐了一上午之后便放弃了。After a fruitless morning sitting at his desk he had given up.罪犯们徒劳地躲闪着探照灯光。The criminals vainly sought concealment from the searchlight.她又徒劳地拉了一下门以后,再也忍不住了,就放声哭了起来.She made one more vain effort and t...
alternating current synchronous交流同步alternating affinity更迭亲力Alternating current reverses from negative to positive about 60 times a second.交流电由负到正一秒钟大约变换六十次.Method: 72 cases of alternating esotropia were divided into symm...