Problem $1$: $(10)$ Explain the differences between black box and white box testing.

Problem $2$: $(10)$ Explain under what situations a matrix test is appropriate.

Problem $3$: $(10)$ Explain under what situation a step$-$by$-$step test is appropriate.

Problem $4$: $(10)$ Explain the differences between unit testing and integration testing.

Problem $5$: $(10)$ Why do we need to do acceptance tests?