One more month, ________, these baby birds will fly out of their nest．

A.or

B.and

C.but

D.otherwise

答案及解析： B

解析：

此题为“祈使句+and分句”的一种变形：“名词短语+and分句”，名词短语表示“条件”，分句表示“结果”。该名词短语补充成从句为：If these baby birds have one more month．(these baby birds will fly out of their nest．)