New words：
calendar [ˈkæləndər] n. 日历；历法；日程表；挂历solar calendar 阳历lunar calendar 阴历
Sample Sentences：
Today is her birthday according to the solar calendar.
I have marked down the date of the party on my calendar.
The fifteenth of each month in the lunar calendar is the day of the full moon.
The Lantern Festival falls on the 15th of the first month of the lunar calendar.
New words：
complex [ˈkɒmpleks] adj. 复杂的；难懂的；费解的
Sample Sentences：
Our culture is more complex than he knows.
The students work in groups on complex problems.
Please change the account password immediately using complex passwords .
New words：
tip [tɪp]
v.翻倒；给…小费
n.提示；小费；指点；实用的提示
Sample Sentences：
Did you remember to tip the waiter?
The mug tipped over, spilling hot coffee everywhere.
He gave the waiter a generous tip.
The following tips can help if you have some of these worries.
New words：
customary [ˈkʌstəˌmeri] adj. 习俗的；习惯的
Sample Sentences：
It is customary to offer a drink or a snack to guests.
Do you really think it's customary to tip the waiters?
It is customary to eat Zongzi during the Dragon Boat festival.
tip [tɪp] v. 翻倒；给…小费
New words：
custom [ˈkʌstəm] n. 习俗；风俗；光顾；（个人的）习惯
Sample Sentences：
It was her custom to rise early.
It is the custom in that country for women to marry young.
The programme was about customs in different parts of the country.