<span>When using the perfect tenses of verbs, it's necessary to add a helping verb, The answer is letter C. Helping verbs helps in conjunction to connect it with a mood or time of the verb. The examples of helping verb are </span><span>will, shall, may, might, can, could, and must.</span>
I think it's c or d, because it basically tells that the statement might be true or it could be false. Also, it talks about how Barack Obama is collaborating with students all around the world.
Among the following words, the choice that you need to double the final consonant before adding the suffix to the base word is, shop + -er. The word shop plus -er becomes shopper with the double consonant p. The rule applied here is that, if the word is only one syllable and ends in a vowel and consonant, double the last letter before the vowel suffix.
It suggest that Sinbad was a maverick, a person who dares to do new things and lookk for fortune and adventure.
