试题详情

We must _______ that the experiment is controlled as rigidly as possible.

Food that（ ）easily must reach the market and the dinner table as quickly as possible.

Our teacher recommended that we ____ as attentive as possible when we visit the museum.

t often chooses the method of the“controlled experiment.”If he wants to find out the effect of light

We must remember that _____fashion is not the most important thing in _______ life.