The matter __be changed into a gas,but it __be heated to its boiling pointcan ``must?can be 可是答案是can ``must

The matter __be changed into a gas,but it __be heated to its boiling pointcan ``must?can be 可是答案是can ``must chan chan He isn't in the school .I think he __be ill.A.can B.must为什么? i like the actor jackie chan best .Jackie Chan is popular _______ the people.Jackie Chan is popular _______ the people. does...matter?原句是：does the preference matter? where is xiao ming?i don't know .He __be in the library.where is xiao ming?i don't know .He __be in the library.A may B might What is the matter? what is the matter? what is the matter? woat`s the matter what is the matter what's the matter? the subject matter是什么意思 what's the matter? the matter of what's the matter?