—Who has taken my pen away? —__________. He was here a moment ago.
_______ has recently been done to provide more buses for the people, a shortage of public vehicles remains a serious problem.
He wondered ________ his son was getting along with the experiment.
In 1492 Columbus and his crew arrived ______ was so-called the New World by the westerners.
—It is _______he often fails in exams_______ makes his parents worried about him. —So, he has to work whole-heartedly.
In some countries, ______ is called “equality” does not really mean equal rights for all people.