超声波波型有()和横波两类,用()表示纵波,T表示横波。
参考答案:纵波 L
At the end of August, another serious quake in Sichuan , _______ has affected 500,000 people, happened about 30 km southeast of Panzhihua City, near the Sichuan-Yunnan border,
A.that
B.where
C.which
D.What
加热制度包括加热时间、()、()和温度制度。