一般现在时与现在完成时辨析 — 英语填空题
题目
用所给动词的正确时态填空（一般现在时或现在完成时）。Astronauts on the space station ___ (do) scientific experiments every day. So far, China ___ (send) several astronauts to the space station, and people on Earth ___ (watch) the news about them carefully every night.