was busy preparing a speech , only_______ once in a while to rise from the table for a tea

(2012·天津)It doesn’t matter ________ you turn right or left at the crossing—both roads lead to the park.

b is not very profitable ________ cash, but Ican get valuable experience from it.

In order to continue to learn by ourselves after leaving school, we must ______ learn how to study in the school now

Have you seen Maragaret? The boss is looking for her everywhere.—She________the train, otherwise she would have arrived here by now.