1.a number of 一些

The research begs a number of questions.
研究绕过了一些问题。

2.participating in 参加

The doctors take turns at participating in the mobile medical team.
医生们轮流参加巡回医疗队。

3.accused of 指控

He was accused of stealing a small boy's bicycle
他被指控偷了一个小男孩的自行车。

4.a first round of 第一轮的

He drew a bye in the first round of the tournament.
他在第一轮比赛中轮空