My sister isn’t in. ________ she comes back, I’ll let her call you back.
We all know travel can ___ our knowledge of the world.A.discoverB.developC.increase
David finds ___ difficult to communicate with his parentsA.one B.it C.this
My cousin Mary was born ___ a singing voice.A.from B.in C.with
--How do you learn English?--I learn English ___ practicing conversations with friends.A.on B.by C.in
—You look very worried. ________ ?—My mother suddenly got ill yesterday.