在托业高级教程中遇到的问题，请大家帮忙看看

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向大家请教几个托业模拟题，都是从托业高级教程中遇到的问题，请大家帮忙看看，谢谢了！！！
If he took Flight 309, he       on time.
A. arrives   B. was arriving  C. would have arrived  D. arrived
答案为D，我觉得有问题，如果是虚拟语气那么正确答案应该是would arrive，如果不是虚拟，那么就应该选B，不管怎样，都觉得不应该选D.

辨析错误
1 After receiving a hospital bill(A), the patient questioned an error(B) in the charges(C) and received the reimbursement(D) from the hospital.
答案为D，不知道为什么？

2 Bored by their routine(A), the supervisor decided his depressed(B) employees need stimulating(C) incentives and instigated their proposed(D) benefit program.
答案为A，why?

3 Their(A) profits they(B) soared in the first quarter due to their(C) new subsidiary, which by itself(D) brought in the highest first-quarter level in company history.
答案为B，我觉得应该是A，把their 改为the才对吧？

4 The committee that was organized(A) to review new policies(B) have(C) already met twice this month and passed(D) two resolutions.
答案为C，我觉得应该是A，在这里committee强调的是集体中的成员，应该作复数名词用吧？那么谓语动词也应该为复数了

5 The important question(A) is how will the new rates give(B) customers regular(C) more options for their basic service(D).
答案为C，我能理解，不过学得有点糊涂了，B中的will位置是不是也不对啊？应该放到give的前头吧？