一种喷洒蔬菜的药水,农药和水的比是1:200.现有2千克农药,需要加水多少千克?
2÷1×200,
=2×200,
=400(千克),
答:需要加水400千克.
________, the gathering crowd burst into applause.
A.On entering the hall
B.When he took the floor
C.The speaker took his place
D.No sooner had the speaker entered
在一棵度为3的树中,若有2个度为3的结点,有1个度为2的结点,则有()个度为0的结点。
A.4
B.5
C.6
D.7