on average 平均
be happy with sth/ sb 对某事/某人满意
for free 免费
such as 例如
encourage sb to do sth 鼓励某人做某事
introduce A to B 把A 介绍给B
pass sth on(to) sb 把某物传递给某人
be available for 对…有用
far (away) from 远离;离开…很远
make sure that 确保;确信
graduate from university 从大学毕业
upon/ on doing 一…就
surf the internet 上网
donate sth to sb 捐赠某物给某人
forget to do sth 忘记去做某事
inform sb of sth 通知某人某事
prepare for 为…做准备
be responsible for 对…负责;是…的原因
be made up of 由…组成
consist of 组成;由…构成;包含有
come up with 想出;提出
tell sb about sth 告诉某人某事
sound like 听起来像
word by word 逐字逐句地
drop some subjects 放弃某些科目
play on the school fields 在学校运动场上玩
e-mail sb 给某人发邮件
talk to sb about sth 关于某事和某人交谈
prepare to do sth 准备做某事
thank sb for 因为…感谢某人
invite sb to do /swh……邀请某人做某事/ 去某地
make a spe