兰花炭疽病可采用多种农药进行防治,其中哪种农药可起到预防作用?()
A.代森锌
B.克菌丹
C.多菌灵
D.甲基托布津
参考答案:A
---_____does he play football after school? --- He always plays football after school.
A.How often
B.How long
C.How much
D.How well
放疗效果较差的恶性肿瘤是()。
A.鼻咽癌
B.淋巴瘤
C.乳腺癌
D.胶质母细胞瘤
E.前列腺癌