1That he will come is certain. 2Whether it will please them is not easy to say. 3What seems easy to some people seems difficult to others. 4Which side will win is not clear. 5Why he did it remains a mystery. 6When they will start is not known yet. 7How he became a great scientist is known to us all. 8Who will take part in the meeting has not been decided. 9Whoever breaks the law will be punished. 10Where she is from is unknown.

Find the subject clauses in the following sentences, and translate them.

思考：主语从句有哪些引导词，这些引导词如何选用？