Before they travel, they __ to buy the airplane tickets. Bbl6epuTe OLMH OTBeT: a. are going to b. shall C. will be able

## Step 1<br />The sentence is about a future action, which is buying airplane tickets before traveling. The correct phrase to use in this context is "are going to". This phrase is used to express a plan or intention for the future.<br /><br />## Step 2<br />The phrase "shall" is not appropriate in this context. "Shall" is used to express a suggestion or a future action that is not a plan or intention.<br /><br />## Step 3<br />The phrase "will be able" is also not appropriate in this context. "Will be able" is used to express the ability to do something in the future, not a plan or intention.