选词填空(可变换形式,其中有两项是多余的)

【小题1】Products made ____________ are usually more popular among consumers.
【小题2】With the decrease of the birthrate, now the old ____________ nearly one-third of the population of the country.
【小题3】If you meet any further problem, contact me ____________.
【小题4】It was his diligence rather than luck that ____________ his success in the competition.
【小题5】Can you ____________ what will happen in the future?
【小题6】I'd like to know what ____________ of students in your school are from the countryside.
【小题7】He is not the person to ____________, for he is always breaking his promise.
【小题8】Now it is unnecessary to ____________ digital watches.