Question

被动语态

He ---- play on the playground just now .
A,was seen to B.was seen C,saw D,is seeing

Answer 1

A。be seen to do被看到做某事。B结构不对。C是主动。D现在进行时不对。
关于B项：能跟不带to 的不定式作补足语的动词有：see,feel,hear,listen to,look at,watch,let,have,make,observe,notice。如：I saw him play in the street just now.而当这些词为被动式时，不定式要带to,如：He was seen to play in the street just now.

Answer 2

A,was seen to

Answer 3

be seen to do
被看到做了某事（全过程）

be seen doing
被看到正在做某事

选A，但是不是很好，因为just now最好是看到正在做的

但选A不会发生语法错误

Answer 4

选A
A。be seen to do被看到做某事。
B结构不对，能跟不带to 的不定式作补足语的动词有：see,feel,hear,listen to,look at,watch,let,have,make,observe,notice。如：I saw him play in the street just now.而当这些词为被动式时，不定式要带to,如：He was seen to play in the street just now.
C是主动。
D现在进行时不对。