下面不是急性胰腺炎血清淀粉酶变化特点的是()

A．发病后数小时升高

B．4～5日降至正常

C．24h达到高峰

D．1～2周降至正常

—_________is very interesting to swim in the river in summer, but it’s dangerous.

A．This

B．That

C．It

D．He