New words：

solar ['səulər] adj. 太阳的；太阳能的

Sample Sentences：

There are nine planets in the solar system.
Solar energy can be transformed into power.
We can use the solar energy to make electric and get warm.

New words：

convert /kənˈvɜːrt/ v.转换；转化；(使)转变

Sample Sentences：

Coal can be converted to gas.
Water is converted into steam if it is boiled.
He wanted to convert his dollars into Chinese Yuan.
The solar cell can convert the energy of sunlight into electric energy.

New words：

snack [snæk]
n.小吃；点心；快餐
v.吃点心（或快餐、小吃）

Sample Sentences：

She likes to snack while watching TV.
I'm not very hungry a small snack is fine for me.
He converted his truck into a mobile snack bar.

convert /kənˈvɜːrt/ v.转换；转化；(使)转变

New words：

litter [ˈlɪtər]
v.乱扔；使乱七八糟；使凌乱；使遍布
n.垃圾；废弃物；乱七八糟的东西；乱放的杂物

Sample Sentences：

The streets were full of litter.
There were piles of litter in the streets.

The streets were littered with rubbish.
He littered the yard with bottles and cans.

New words：

ice-lolly ['lɔli] n.冰棍；冰棒
popsicle ['pɔpsikəl] n. 冰棒；冰棍
ice candy n. 冰棒

Sample Sentences：

In England a popsicle is called an ice lolly.
I like to eat ice lolly, ice-cream and water ice.