英语从句题

英语从句题
1._____a certain doubt among the people as to the practical value of the project.
A it has B they have C it remains Dthere remains
为什么?
2Could I speak to ______ is in charge of internationalsales please?
A who Bwhat Cwhoever D WHATEVER
为什么A不能用
3 Some children want to challenge themselves by learning a language different from ______their parents speak at home.
A what Bthat C WHICH D one
为什么是B,A 不行
4students are slways interested in finding out _____they can go with a new teacher.
A how far B how soon C HOW often D how long
为什么.