Secondary rainbows are unusual because the light is reflected twice within the raindrop before it (4) ______ a rainbow, so the colors are in reverse order and not as bright as primary rainbow

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Secondary rainbows are unusual because the light is reflected twice within the raindrop before it (4) ______ a rainbow, so the colors are in reverse order and not as bright as primary rainbows.

forms

grows

develops

shapes

Giải thích

A. forms

👉 “light … forms a rainbow” = ánh sáng tạo thành cầu vồng → dùng đúng ngữ cảnh khoa học.