动词不定式问题,关于前面加不加逗号

动词不定式问题,关于前面加不加逗号
1.David threatened____his neighbour to the police if the damages were not paid.
A.to be reported B.reporting C.to report D.having reported
句意：大卫威胁说,如果损坏没有得到赔偿的话,他就把邻居告到警察那去.Threaten to do sth威胁要做某事.故选C项.
2.Schools across China are expected to hire 50,000 college graduates this year as short-term teachers,almost three times the number hired last year,____ reduce unemployment pressures.
A.help B.to have helped C.to help D.having helped
点拨：to help的逻辑主语是schools,表示目的.
不定时常用作目的状语或表示事与愿违的结果,但前面不加逗号.
1：第二题解析 不是说不定时可做目的状语吗,前面不加逗号,那第一题为什么就可以加逗号了呢 ,也是目的状语啊.
还是说表示事与愿违的结果时前面不加逗号,是不是有 he came home,only to find she is away.不定时表示事与愿违时前面一定要有个only啊just什么的?
厄第一题给错了。
1.Lots of rescue workers were working around the clock,____ supplies to Yushu,Qinghai Province after the earthquake.
A.sending B.to send C.having sent D.to have sent
不定时常用作目的状语或表示事与愿违的结果，但前面不加逗号。
2.Schools across China are expected to hire 50,000 college graduates this year as short-term teachers,almost three times the number hired last year,____ reduce unemployment pressures.
A.help B.to have helped C.to help D.having helped
to help的逻辑主语是schools，表示目的。
1：第一题解析 不是说不定时可做目的状语吗，前面不加逗号，那第二题为什么就可以加逗号了呢 是目的状语啊。
还是说表示事与愿违的结果时前面不加逗号，是不是有 he came home，only to find she is away。不定时表示事与愿违时前面一定要有个only啊just什么的？