请帮忙指出下列题目所考察的高中英语语法点,

请帮忙指出下列题目所考察的高中英语语法点,
1.—Do you think he can get the firstprize for jumping?
—Impossible now.He to do so,but he has just hurt hisleg.
A.has expected B.isexpected C.would expect D.was expected
2.Notuntil the man in black took off his dark glasses that he was the famous film star.
A.did I realize B.Irealized C.was I realized D.I have realized
3.Space exploration began in the 1960s,and since then about five hundred people into space.
A.have traveled B.traveled C.had traveled D.are traveling
4.—Excuse me,but could you please tell me the way to the gas stationaround here?
—Sorry.There isn’t gas station nearby,I'm afraid.
A.one B.不填 C.the D.a