关于声现象,下列说法正确的是[ ]
A.只要发声体振动,我们就可以听到声音
B.一切能发声的物体都在振动
C.声音在液体中比在固体中传播得慢些
D.振动停止了,声音能继续传播
答案:D
The writer ___ his writing so that he forgot to have his lunch.
A.absorbed
B.was absorbed into
C.absorbed into
D.was absorbed in
生物质发电技术分成哪两种?()
A.直接燃烧发电
B.气化发电
C.填埋法发电
D.温差发电