1．In times of economic crisis, though they have confidence in their investments, many investors are more ________ (caution) about their investment strategies.
2．Facetoface conversations are ________ (benefit) to the promotion of understanding, which is why communication matters.
3．I saw Bob play the piano at John's party and on that occasion he was ________ (simple) brilliant.
4．Recycled water is probably much ________ (pure) than anything most living Californians have drunk previously.
