The newly published book, which refers _______ basic English grammar, is _______only for beginners.

A．as; meant

B．for; intended

C．to; planned

D．to; intended

典型的疟疾发作包括周期性的发冷、发热和出汗退热三个连续的阶段。发作的基本动因是患者血液中的疟原虫达到了一定数量，即（）。