When heated, water changes into ( ).

[单选题]The water level in the gauge glass when a boiler is operating is _____ when the boiler is shut down.A．lower thanB．higher thanC．belowD．equal to

[单选题]When the water produced from most evaporator is supplied for drinking purpose, it must be treated to ensure it is biologically pure and _____.A．slightly acidicB．slightly alkalineC．no saltyD．slightly bitter

[单选题]Water, when boiled, always ______ steam.A． gives inB． gives upC． gives offD． gives away

When a pencil is partly in a glass of water, it looks as if it__________.A. brea

The water ______ cool when I jumped into the pool for morning exercise.A. was fe

The water ______ cool when I jumped into the pool for morning exercise．（ ）A. was

Make changes when necessary. check in arrange inconvenience fortune

Experts say that the unnecessary ingredients can be filtered ____ when water i

Rainbows___________when sunlight passes through small drops of water in the sky.

[单选题]When students are asked to find out the changes of their hometown and make