You can't play the guitar in the classroom．（改为祈使句）
the guitar in the classroom．
It rained （大） on my way home yesterday afternoon．
You must look at the traffic lights before you go （穿过） the road．
I left my book at home．May I borrow （你的）？
In the USA，people eat with （刀） and forks．
The number 13 is considered an （lucky） number in some Western countries．Many hotels and tall buildings don't have a 13th floor or a Room 13．