New words：
millimetre [ˈmɪlɪˌmitər] n.毫米；千分之一米millimeter [ˈmɪlɪˌmitər] n.毫米；千分之一米
Sample Sentences：
One centimetre equals ten millimetres.
These jellyfish were only one millimetre long.
Brisbane recorded 790 millimetres of rain in a week.
The land moves northwest by four millimetres per year.
New words：
centimetre [ˈsentɪˌmitər] n. 厘米
centimeter [ˈsentɪˌmitər] n. 厘米
Sample Sentences：
There are 2.54 centimetres to an inch.
One hundred centimeters make one meter.
One centimeter is equal to 10 millimetres.
Mr Zebra is 10 centimetres taller than Mr Deer.
millimetre [ˈmɪlɪˌmitər] n.毫米；千分之一米millimeter [ˈmɪlɪˌmitər] n.毫米；千分之一米
New words：
seldom [ˈseldəm] adv.很少；难得；不常
seldom在句中的位置通常是紧靠动词，放在实义动词之前，特殊动词（如be动词、情态动词、助动词）之后。
Sample Sentences：
Barking dogs seldom bite.
My cat is seldom noisy at night.
This baby seldom cries unless he is tired.
It is seldom that we have a picnic in winter.
New words：
broadcast [ˈbrɔdˌkæst]
v.广播；播送（电视或无线电节目）；传播
n.广播节目；电视节目
Sample Sentences：
She broadcast the secret to everyone.
The interview was broadcast live across Europe.
The TV station will broadcast a new cartoon tonight.
The morning news broadcast starts at 7 AM.
The weather broadcast said it will rain tomorrow.
New words：
broad [brɔd] adj. 宽阔的；广阔的；广泛的
Sample Sentences：
The road is broad enough for two cars.
The book covers a broad range of topics.
He was six feet tall, with broad shoulders.
We saw a broad desert under the blue sky.