雄蕊由（）组成。
A.花药和花粉
B.花药和花丝
C.花药和花粉囊
D.花粉母细胞和花丝
参考答案：B
My cousin Linda is weak in English. She asked me _________________.
A．how is the best way to learn English
B．how could she learn English well
C．how she can learn English well
D．what the best way to learn English was
发电机-变压器接线，当变压器重瓦斯保护动作时，变压器各侧断路器将跳闸。
