雨量筒的承雨器与承雪器的不同就在于承雨器带漏斗,而承雪器不带漏斗。
参考答案:对
在预测声级前需根据声源与预测点之间的空间分布形式将声源简化成( )几类。
A.点声源
B.线声源
C.面声源
D.体声源
Pre-entry refers to the () of Customs entry documents for an export consignment before it actually leave the country.
A. report
B. submission
C. issue
D. order