new bridge has been built over Changjiang River in Huangshi.
David finds ___ difficult to communicate with his parents A.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.
I found _____ necessary to save energy and protect the environment.