【单选题】According to the author, swans in captivity are______.
A.
happy unless their wings have been cut
B.
happy most of the time, but unhappy sometimes
C.
unhappy most of the time
D.
only happy when they are bringing up families
【单选题】—Julia looks very happy!She________have passed the TOEFL. —I suppose so.It can't have been too difficult for her,anyway. [ ]
【判断题】冷剂在充灌前必须经过干燥脱水处理后方科使用。
【简答题】As my own studies have advanced, I have been increasingly impressed with the functional similarities between insect and vertebrate societies and less so with the structural differences that seem, at f...