[填空题]When (heat) （）, water can be changed into vapour.

[填空题]When (heat)（）, water can be changed into vapour.

[填空题]When (heat) ______ , water can be changed into vapour.

[填空题]When (heat) ______, ice will be changed into water.

[填空题]When (heat)（）, iron can be changed into liquid.

[填空题]When (heat) ______ , iron can be changed into liquid.

[填空题]When (heat) ______ , ice changes into water.

[填空题]We all scream for water when thirsty, but do you know in very hot, dry weather, plants also make{{U}} (36) {{/U}}sounds as if they are crying out for help You see, in a plant stem there are hundreds of water pipes that bring water and{{U}} (37) {{/U}}from the soil all the way up to the leaves. As the ground{{U}} (38) {{/U}}dry, it becomes harder and harder for the plants to do this. In{{U}} (39) {{/U}}draughts, plants have to fight to pull out any water{{U}} (40) {{/U}}. Scientist Robert Winter has found out that when it is really bad their water pipes snap(绷断) from the{{U}} (41) {{/U}}like rubber bands. When that happens, the whole plant vibrates(振动)a little. The snapping pipes make noises ten thousand times quieter than a{{U}} (42) {{/U}}. Robert knows that healthy,{{U}} (43) {{/U}} plants are quiet.{{U}} (44) {{/U}}. How do the insects know which are healthy plants and which are not Robert thinks that the insects may listen for the plants that cry and then they m