With the computer's system _______. it can't be used at the moment.

Tom worked very hard,  ______ that he would be able to buy a car of his own in two years.

Smiles around the world _____ be false, ______ other feelings like anger, fear or worry.

—What’s made Mr. Grey so sad?—_____ three tickets to the pop art exhibition.

_____ her mother after being separated for 20 years, she couldn’t help, even though she tried not to, ______.