A.取兩個(gè)測(cè)點(diǎn),位置一般在相對(duì)水深0.2、0.8處 B.取3個(gè)測(cè)點(diǎn),位置為相對(duì)水深0.2、0.6、0.8處 C.特殊情況下,僅在水面一點(diǎn)處開(kāi)展試驗(yàn) D.特殊情況下,僅在相對(duì)水深0.6一點(diǎn)處開(kāi)展試驗(yàn)
A.100s B.1000s C.2000s D.4000s
A.1%~5% B.2%~5% C.2.5%~5% D.3%~5%