A.春季 B.夏季 C.秋季 D.冬季
A.10~30s B.10~20s C.20~30s D.10~40s
A.覆蓋養(yǎng)護 B.灑水養(yǎng)護 C.化學劑養(yǎng)護 D.自流養(yǎng)護