1.Don't ___（喊）at others when you are angry. 2.Students mustn't ___（扔）rubbish about water in
1.Don't ___（喊）at others when you are angry.
2.Students mustn't ___（扔）rubbish aboutin the school.
3.Yesterday I saw a factory ___（倒）waste water into the river nearby.
4.When did your father ___（到达）?
5.My friend is going to get ___（结婚）next week.
6.When aomeone gives you a present,you must open it _i____.