金丝桃与金丝梅最明显的形态区别是（）。
A.枝圆柱形与两棱形
B.叶长椭圆形与长卵形
C.花单生与簇生
D.雄蕊长于花瓣与短于花瓣
参考答案：D
Nancy hasn’t begun on her PH.D ________ working on her master’s degree.
A. still because she is yet
B yet as a result she is still
C yet because she is still
D still while she is already
面粉应储藏于（）
A.阴凉干燥
B.阴凉潮湿
C.高温多湿
D.阳光直射之处
