Notice the word Should, which is followed by the verb with helping verbs are verbs, infinitive or 1 slot, but always by becoming a verb is (-ing) is a word that the following should therefore be filled no follow ing.
Should be noted that the verb. Will be followed by a verb is always the first or infinitive verb followed by a verb form are doing (-ing) is the following should be modified so as not to fill the follow ing.
Observe the Should which is a verb, followed by a verb or infinitive channel 1 always แต่กริ drugs after a verb is doing. (- ing) is the following should therefore be solved follow added ing.