He arrived at last, ______________.

Do remember to be________. We must avoid any possible risks when doing this dangerous chemical experiment—burns, poisonous gases or cuts from broken tubes.

_______ the children grew old, they became more and more _______ in science.

Tom is a hard-working student．In fact, you cannot find anyone in the class ____．

Although he was disabled when he was only ten years of age,yet he aimed _____,for which his classmates spoke ______of him.