-Dirty water shouldn’t be poured into rivers.-_______. It will cause pollution.
---He has never spoken to a foreigner. ---________.
---I don’t know if his uncle ________. --- I think he ________ if it doesn’t rain .
The boy is afraid ________ cross the bridge, because he is afraid ________ falling into the river.
The writer found ________ difficult ________ English.
The English teacher added that having conversations ________ friends was not ________ at all.