If we had taken such effective measures much earlier, the river___ soseriously now.

Please send ________ best wishesto Mary.

There is no need _______ and it’s no use__________ there too early.

(2013·湖南长沙四校二模)—Is the letter from your mother?—Yes.But she ________the letter herself，because she doesn’t even know one word.

Work hard________ you will succeed.[ ]