. This sentence needs ___________ .
There are _______ approaches to English teaching. But not all of them are equally efficient for our Chinese students.
.After Wenchuan earthquake, the unaffected provinces ______ skilled builders to the quake-hit areas quickly.
I hate__________when people talk with their mouths full.
_____ other good students, Hank is _______one.
You can’t become infected_______ HIV by swimming in a pool, or sitting in a bath.