He didn't go to the party, but he does wish he there. A.
would be B.
has been C.
would have been D.
had been

单项选择题

工程中更常见的是单代号网络图。（    ）

判断题工程中更常见的是单代号网络图。（    ）

催化DNA子链延长的酶主要是 A. DNA聚合酶I ...

单项选择题 催化DNA子链延长的酶主要是 A.
DNA聚合酶I B.
DNA聚合酶II C.
DNA聚合酶III D.
DNA连接酶