【判断题】1860年到1910年,是美国农业的半机械化时期。
【单选题】_____he made an important speech at the meeting was true.
【单选题】—Mr Jackson, _______ we go rock climbing? —Yes, but you must use ropes. [ ]
【单选题】he made an important speech at the meeting was true.
【单选题】MDS 中所指的发育异常,是指该系异常细胞占该系细胞的比例是
【单选题】-Must you go?. -Yes, I' m afraid I really ________.