Can you me out ? (will medal if correct) even though streams that flow through valleys generally move very fast, the stream load is mostly made of suspended load. usually, bed load is only found in mountain streams with a high gradient. why? a: rocks and boulders are only found in gullies which are in the mountains b: streams with low gradients usually move slowly and cannot carry bed load downstream c: large rocks and boulders just aren't very common at lower elevations d: both a and b