The missing boys were last seen ________ near the river.
A、playingA
所填的词为主语补足语，因其后有明确的地点，补足语表示动作当时正在进行中，所以只能使用playing。
________ he has many friends, he is often feeling lonely.
Pleasewriteareport________theabovesubjectsaretobecovered.
As for family education, parents are encouraged to rely on ________ rather than punishment.
______aretheprimarydestinationsfortheChineseatpresent.
The missing boys were last seen ________ near the river.
