✔ 最佳答案
B
HK students always assume a sentence with (that) is the correct answer and a sentence without is wrong. In fact (that) in a connective sense is not required in most cases because it was assumed to be there. The problem of D is (it very interesting to be a tourist guide) is a wrong sentence (missing verb). If it was supposed to be written like that then it should be (found that it is very interesting to be a tourist guide).
B is a complete sentence which doesn't required a (that). (He found it very interesting to be a tourist guide), (it) represents (to be a tourist guide). (He found the boy very naughty.) (He found it very troublesome to deal with those office ladies). All these sentences share a same structure and all are correct.
C is incorrect because (find[or found]) in this sense is a transitive verb which required an object after the verb. You can find (nothing) after a search, but you can't find ( ).
A is incorrect because two verbs were used (found is)