对那些是否有明显的裂纹，用铆钉连接的零件是否松动，都可用小锤轻轻敲击，金属声音清脆，说明零件的状况良好。
参考答案：对
There was a tree in front of the house, ___ owner was seen sitting under it, enjoying the shade.
A．whose
B．where
C．which
D．that
预防与克服中耳气压性耳压的措施是（）.
A.运动软腭法、吞咽法；
B.憋气法、深呼吸法；
C.压耳法、运动头部法。
