The influence of shape of aggregate in strength and workability of concrete are given below in statements S1, S2, S3 and S4. Which of the statements are correct?

S1: Rounded aggregate produces concrete with high workability and low strength.

S2: Angular aggregate produces concrete with high workability and low strength.

S3: Rounded aggregate produces concrete with low workability and high strength.

S4: Angular aggregate produces concrete with low workability and high strength.