New Words：
define [di'fain] v. 规定；定义；界定；明确；解释
definition [.defi'niʃən] n. 定义；阐释
Sample Sentences：
How do you define right and wrong?
Please listen while I define your duties.
The powers of the police must be clearly defined.
What's your definition of happiness?
What is Happiness in your definition?
New Words：
cliff [klif] n. 悬崖, 峭壁
nightmare ['nait.mer] n. 恶梦；梦魇；极其糟糕的情况
Sample Sentences：
It's almost impossible to climb up the cliff.
There are very few holds on the cliff face.
I have nightmares about falling off a cliff.
Her first few days in that foreign land were a total nightmare.
New Words：
zip wire 滑索
pulley ['puli] n. 滑车, 滑轮, 皮带轮
Sample Sentences：
Have you tried the zip wire before?
What do you do with a zip wire?
You slide down the rope with the help of a pulley.
A pulley is made from wheels and rope. With the pulley, we can pull things easily.
New Words：
slip [slip] v. 溜；滑倒；滑脱；溜走
Sample Sentences：
The fish slipped out of my hand.
The student slipped out of the classroom.
I grabbed him, but he slipped from my grasp.
He caught the ball, then it slipped through his fingers.
New Words：
grasp [grɑ:sp]
v.抓住；理解；领会；抓紧
n.紧抓；紧握；控制；领会
Sample Sentences：
The little girl grasped her mother's arm.Grasp my hand and I'll pull you over the wall.
They have a good grasp of foreign languages.
He let the ball slip through his grasp and into the net.
slip [slip] v. 溜；滑倒；滑脱；溜走