森林不但能制造氧气，还能分泌杀菌素，净化空气．1公顷森林每天分泌杀菌素54千克，1公顷森林1星期能分泌杀菌素多少千克？
直接写出得数．+=﹣+=+=﹣=+=+=++=﹣=+= 3﹣﹣=
直接写出得数﹣=﹣=﹣=+=+=﹣=+=﹣=
直接写出得数．+=﹣=+=﹣= 10﹣﹣=====．
直接写得数===== 1﹣= 1﹣==
直接写出得数.+= 1﹣=﹣= 2.5×3.8×4=+= 10﹣9.12=+0.25= 0.65×9+0.65=
+
=
﹣
+
=
=
﹣
=
+
=
+
=
+
+
=
﹣
=
+
= 3﹣
﹣
=
﹣
=
﹣
=
﹣
=
+
=
+
=
﹣
=
+
=
﹣
+
=
﹣
=
+
=
﹣
=
﹣
=
=
=
=
=．
=
=
=
=
= 1﹣
= 1﹣
=
=
+
= 1﹣
=
﹣
= 2.5×3.8×4=
+
= 10﹣9.12=
+0.25= 0.65×9+0.65=
粤公网安备 44130202000953号